Dave Sanders had never talked about regret before. Not to Frank DeAngelis. They talked every day, they had been close for twenty years, but they had never gone there.

It came up unexpectedly, on Monday afternoon. Frank strolled out to the baseball diamond to watch his boys take on archrival Chatfield. He had coached the team before he went into administration, alongside his old friend Dave Sanders. And there at the top of the bleachers was Dave watching right now. He had a couple hours to kill until his girls arrived for basketball practice. The season was over, but they were working fundamentals for next year. Dave could have spent the time grading papers, but it was hard to fight the lure of the field.

Mr. D said hi to the kids excited to see him there, then sat down next to Dave. They talked for two hours. They talked about everything. Their entire lives. Coaching, of course. The first time they met, when Frank arrived at Columbine in 1979. He was one of the shortest teachers on the faculty and the principal recruited him to coach basketball. "They needed a freshman coach, and I was on a one-year contract," Frank said. "The principal said, 'Frank, if you do me this one favor, I owe you one.' And what am I gonna say? 'I'll do whatever you want, sir.' So I coached basketball."

The conversation was lighthearted for a long time, Dave cutting up as usual. Then he turned serious. "Do you miss coaching?" he asked.

"Not really." Frank's answer sort of surprised Dave. Coaching was his life, Frank explained, but he had never really left it. He'd just expanded his audience.

"You think so?" Dave wondered.

Oh, yeah, Frank said. You can't really teach a kid anything: you can only show him the way and motivate him to learn it himself. Same thing applies to shortstops turning the double play and students grasping the separation of powers in the U.S. government. It's all the same job. Now he had to coach teachers, too, to inspire their own kids to learn.

"What about you?" Frank asked. "Any regrets?"

"Yeah. Too much coaching."

They shared a good laugh.

Seriously, though, Dave said. His family had come second to coaching. God. His family came second.

Frank suppressed another laugh. His own son, Brian, was nineteen. Frank was confident he had been a good dad, but never enough of one. It had rankled his wife since day one, and recently she had laid into him about it: "When are you going to stop raising everybody else's kids and start raising your own?"

That stung. It was a little hard to share, but this seemed like the moment, and Dave seemed like the guy. Dave understood. It was bittersweet for both of them. They had reached middle age blissfully. They wouldn't change a moment for their own sake--but had they shortchanged their kids? Frank's son was grown now, and Dave's daughters were, too. Too late. But they were still young women, and Dave had five grandkids and was hoping for more. Dave had not told the other coaches he was cutting back yet. He had not announced his decision to take off the first summer in memory. He confided it all to Frank now.

What an amazing guy, Frank thought. He thought about hugging Dave. He did not.

The game was still going, but Dave got up. "My girls are waiting for me," he said. "I have open gym."

Frank watched him walk slowly away.

Coach Sanders had something else on his mind. He had held his first team meeting last Friday, and his new team captain, Liz Carlston, had failed to show. He expected to see her tonight. It was going to be a tense conversation, and it wasn't going to be just her.

Sanders sat all the girls down on the court. They talked a lot about dedication. How was it going to look to the freshmen if the team leaders mouthed the words, then failed to show up? He expected a one hundred percent commitment. Every practice, every meeting, or you're out.

He told them to scrimmage. He let them keep at it the entire evening. He sat on a folding chair watching, analyzing, preparing.

At the end of the night, Liz tried to summon the courage to talk to him. She had just blanked on the meeting; she hadn't meant anything by it. She felt guilt and fear and anger. He wouldn't actually cut her, would he? Why hadn't he given her a chance to explain?

She stopped at the baseline to change her shoes. Coach Sanders was right there. She should talk to him.

She walked out quietly. She didn't even say good-bye.

Linda Lou was asleep when Dave got home that night. He kissed her softly. She woke up and smiled.

Dave was holding a wad of cash--a thick stash, seventy singles. He flung them toward her and they fluttered down onto the comforter. She got excited. She loved his little surprises, but she wasn't sure what this was about. He went with it for a minute, got her hopes up, and then said she was silly: it was for her mom. Linda's mom was turning seventy on April 20. She liked to gamble. She would like that.

Dave was all laughs that might with Linda. She was shocked when she learned later how tense his evening had been.

"That's how the man could change," she said. "Walk through our door and he was done with basketball. Now he was thinking of my mom."

He went down to fix himself a Diet Coke and rum. He found a game. Linda fell back asleep with a smile.

Morning was less pleasant. The alarm buzzed at 6:30. Linda and Dave were both in a rush. Linda had to pick up balloons for her mom's birthday party, and Dave had to drop Linda's poodle off for a haircut.

Dave had no time for breakfast. He snagged an energy bar and a banana for the car. It was trash day-- his job, but he was going to be late. He asked Linda if she would do it.

She was too stressed. "I really don't have time today."

"I'm really going to be late," he muttered.

They rushed out to separate cars and realized they had forgotten to kiss good-bye. They always kissed good-bye.

Dave blew her a kiss from the driveway.

10. Judgment

On Tuesday morning, the boys rose early, as usual. It was dark but warm already, set to soar into the eighties, with blue skies, perfect for their fires. It was going to be a beautiful day.

Dylan was out of the house by 5:30. His parents were still in bed. He called out "Bye," and shut the door behind himself.

They skipped bowling class and went straight to work. Dylan scrawled the schedule into Eric's day planner under the heading "make TODAY count." Eric illustrated it with a blazing gun barrel.

First stop was the grocery store, where they met up to acquire the last of the propane tanks: two for the cafeteria, two for each car, and two for the decoy. The big bombs were the heart of the attack. Eric had designed them months before but had left acquisition to the final morning. The boys had stashed most of the arsenal in Eric's bedroom closet, and he had faced a couple of close calls with his parents already. Hiding a cluster of twenty-pound tanks in there was out of the question.

They returned to Eric's house at 7:00 and then split up: Eric filled the propane tanks, Dylan got the gasoline. They allotted half an hour to assemble the big bombs and set up the cars, and an hour for one last round of gear-up, practice, and "chill." They got something to eat. Dylan apparently had potato skins.

Several friends noticed peculiarities. Robyn Anderson was surprised to see Dylan a no-show for calculus. He had sounded fine on the phone the previous night. Then a friend told her Eric had been missing from third hour. The boys cut an occasional class together, but never an entire morning. Robyn hoped Dylan wasn't sick; she made a mental note to call once she got home.

Their friend Brooks Brown had a stronger reaction. Eric had missed a test in psychology class. What kind of stunt was that? What kind of stunt was that?

Chill time was over. It had gone on too long, perilously over schedule. Shortly before 11:00 A.M. A.M., Eric and Dylan set off with the arsenal. Dylan wore cargo pants, a black T-shirt printed with WRATH WRATH, and his Red Sox cap turned backward, as usual. His cargo pockets were deep enough to conceal most of the sawed-off shotgun before he pulled on the duster. Eric's T-shirt said natural selection. They both wore black combat boots and shared a single pair of black gloves--the right on Eric, the left on Dylan. They left two pipe bombs behind at Eric's house, six at Dylan's. Eric laid a microcassette on the kitchen counter with some final thoughts. They also left the Basement Tapes, with a final good-bye recorded that morning.

They drove separate cars to a park near Eric's house, dumped the decoy bomb in a field, and set the timers for 11:14. Combat operations were under way.

They hopped back in their cars and headed for the school. They had to hustle now. The last few minutes were critical. They couldn't plant the big bombs until "A" lunch began. Fourth period ended at 11:10. Once the bell rang, they had seven minutes to carry the bombs in, navigate the turbulent lunch crowd, stash the bombs by the designated pillars, get back to their cars, gear up, take cover, and prepare to attack.

Eric pulled into the parking lot at 11:10, several minutes behind schedule. A couple of girls spotted his car as they headed out for lunch. They honked and waved. They liked him. Eric waved back and smiled. Dylan followed him in. No waves.

Dylan drove to his normal spot in the senior lot and parked his BMW directly in front of the cafeteria. When the attack began, this would afford him a clear sweep of the southwest side of the building: the long, wide arc of green-tinted windows that wrapped the commons on the first floor and the library above.

Eric continued on to the small junior lot, about a hundred yards to Dylan's right. Eric had the choice spot, directly facing the student entrance, where the bulk of the survivors would presumably flee. He could also cover the full southeast side of the building and interlock his fire with Dylan's to his left.

Brooks Brown walked out for a cigarette and spotted Eric parking in the wrong lot. Brooks charged up to confront him about the test; by the time he got there, Eric had stepped out and was pulling out a big hulking duffel bag.

"What's the matter with you?" Brooks yelled. "We had a test in psychology!"

Eric was calm but insistent. "It doesn't matter anymore," he said. "Brooks, I like you now. Get out of here. Go home."

Brooks thought that was strange. But he shook his head and walked on, away from the school.

Eric's friend Nate Dykeman also caught sight of him arriving, and also found the circumstances strange.

Eric headed in with his duffel. By 11:12, they were scheduled to be back at their cars, arming up. A surveillance tape time-stamped 11:14 indicates they had still not entered the commons. They had less than three minutes--the timers were set for 11:17. There was only a modest chance that they could make it to safety in time. And they could hardly have hoped to be locked and loaded when the bombs blew.

They could have reset the timers and sacrificed a few casualties. That would have required coordination, as they had parked across the lot from each other and it would be risky to expose the bombs inside the cafeteria. They could have abandoned the plan, but the decoy bombs might already be exploding.

Shortly after 11:14, they entered the commons. They moved inconspicuously enough to go unnoticed. Not one of the five hundred witnesses noticed them or the big, bulky bags. One of the bags would be found inches from two tables strewn with food.

They made it out, and armed quickly. It was just like the drill, except this time each was alone--close enough for hand signals, too far to hear. They strapped on their arsenals, covered them with the dusters. Time was tight and they broke with their drill, leaving the shotguns in the duffel bags. Each boy had a semiautomatic against his body, a shotgun in his bag, and a backpack full of pipe bombs and crickets. This is probably the moment they set the timers on their car bombs. It would just be a matter of seconds now. Hundreds of kids dead. As far as they knew, they had instigated mass murder already. The timers were winding down. Nothing to do but wait.

Surveillance cameras should have caught the killers placing the bombs. They would have, if either the bombers or the custodian had been on time. Every morning, the custodian followed the same routine: a few minutes before "A" lunch, he pulled out the prelunch tape and set it aside for later viewing. He popped an old, used tape into the machine, rewound it, and hit Record. Rewinding took up to five minutes, meaning a brief pause in taping. Kids could leave all the garbage they wanted during that window, but hardly anyone was around to do so.

The custodian was running late on Tuesday. He hit the stop button at 11:14, and no bombs were visible; neither was Eric or Dylan. While waiting out the rewind, the custodian got a phone call. He talked, and the tape sat a little longer. He got the new tape in and hit Record at 11:22, leaving an eight-minute gap. The first frame shows the bombs visible and students near the windows beginning to react. Something peculiar outside has caught their attention.

Columbine ran on a bell schedule, and most of its inhabitants followed a strict routine. Several of them had broken it Tuesday morning. Patrick Ireland, the junior afraid to ask Laura to the prom, liked variety. Some days he spent "A" lunch in the library, others in the cafeteria. He had stayed up late talking to Laura on the phone again, and still had to finish his stats homework. So he headed to the library with four of his buddies as Eric and Dylan positioned the duffel bags. Patrick sat down at a table just above one of the bombs.

Cassie Bernall, the Evangelical junior who had transferred to Columbine to enlighten nonbelievers, pulled up a chair near the window. It was unusual to find her in the library at this hour. She was also behind on her homework, trying to complete an English assignment on Macbeth Macbeth. But she was happy she had finished the presentation she would be making to her youth group that night.

Mr. D was oddly absent from the cafeteria. His secretary had booked an interview, delaying his rounds. He sat in his office at the opposite end of the main corridor, waiting for a young teacher to arrive. Mr. D. was about to offer him a permanent position.

Deputy Neil Gardner, the community resource officer, worked for the sheriff's department but was assigned full-time to Columbine. He normally ate with the kids, and "A" lunch was his optimal chance for bonding, a key element of his job. He wore the same security uniform with the bright yellow shirt every day, so he was easy to spot. Tuesday, Gardner took a break from his normal routine. He didn't care for the teriyaki on the menu, so he went for takeout from Subway with his campus boss-- an unarmed civilian security guard. It was a beautiful day, lots of kids were outside, so they decided to check out the smokers. They ate their sandwiches in Gardner's squad car, in the faculty lot beside the smokers' pit on the opposite side of the school.

Robyn Anderson sat in her car nearby. She had driven out of the senior lot just about the time Eric and Dylan were hauling the bombs in, but had missed them. She'd swung around the building to pick up two friends. She got antsy--lunchtime was slipping away. Five minutes passed, maybe ten. Finally, the girls appeared. Robyn snarled at them, and they drove off. On the opposite end of the school, shots had already been fired.

A freshman named Danny Rohrbough went to the commons to meet up with two buddies. After a few minutes, they decided to head out for a smoke. If the bombs had worked, that choice might have saved him. He might have gotten out just in time. They headed out a side exit at the worst moment, directly alongside the senior parking lot.

The bombers spent a minute or two by their cars. They knew the diversionary bomb should have already blown three miles to the south. In fact, it had fizzled. A surveyor working in the area had moved it, and then the pipe bombs and one of the spray cans had detonated, producing a loud bang and a grass fire. But the propane tanks--the main explosive force--lay undisturbed in the burning field. The decoy was Eric's only big bomb to ignite at all, but one of his dumber ideas. Officials learned of it just as the shooting started, four minutes before the first call from the school. The chief effect was to alert authorities that something was amiss in the area. Nothing of consequence was diverted.

Eric and Dylan had to proceed on faith.

As far as Eric and Dylan knew, cops were already speeding south. They would see the commons disintegrate, though. Each car was positioned for a perfect view. The cafeteria would explode in front of them; they would watch their classmates be torn apart and incinerated, and their high school burning to the ground.

11. Female Down

At 11:18, the school stood intact. Some kids had already made it through the lunch lines and were strolling outside, settling onto the lawn for a little picnic. No sign of disturbance. The timing devices were not precise. No digital readouts with seconds counting down in red numerals; they were old-fashioned clocks with a third little alarm hand positioned two-fifths of the way between the 3 and the 4. But they should have blown by now.

Hundreds of targets streamed out the student entrance. They hopped into their cars and zipped away. Time for Plan B. There was no Plan B. Eric had staggering confidence in himself. He left no indication that he planned for contingencies. Dylan left no indication that he planned much of anything.

They could just proceed to Act II: mow the departers down in a cross fire and advance on the exits as scripted. They still could have topped McVeigh. But they didn't. The bomb failure appears to have rattled one of the boys.

No one observed what happened next. Either boy might have panicked, but Eric was unflappable, the reverse of his partner. The physical evidence also points to Dylan. Eric apparently acted swiftly to retrieve his emotional young partner.

We don't know whether they employed their hand signals, or how they came together. We know that Eric was in the prime location yet abandoned it to come to Dylan's. And Eric moved quickly. Within two minutes, Eric had figured out that the bombs had failed, grabbed his packs, crossed the lot to Dylan's car, rushed with him to the building, and climbed the external stairs to the west exit. That's the first place they were observed, at 11:19.

Their new position set them on the highest point on campus, where they could survey both lots and all the exits on that side of the building. But it took them away from their primary target: the student entrance, still disgorging students. They could no longer triangulate or advance aggressively without separating.

At 11:19 they opened the duffel bags at the top of the stairs, pulled out the shotguns, and strapped them to their bodies. They locked and loaded the semiautomatics. One of them yelled, "Go! Go!" Somebody, almost certainly Eric, opened fire.

Eric wheeled around and shot at anyone he could see. Dylan cheered him on. He rarely fired. They hit pedestrians among the trees, picnickers to the south, kids coming up the stairs to the east. They tossed pipe bombs down the stairs, into the grass, and onto the roof. And they shared a whole lot of hoots and howls and hearty laughs. What a freaking wild time.

Rachel Scott and her friend Richard Castaldo were the first down. They had been eating their lunch in the grass. Eric shot Richard in the arms and torso. He hit Rachel in the chest and head. Rachel died instantly. Richard played dead. Eric fell for it.

Danny and his smoking buddies Lance Kirklin and Sean Graves were headed up the dirt path toward the stairs. They saw the gunmen firing, but assumed it was a paintball game or a senior prank. It looked like fun. They rushed straight toward the shooters, to get closer to the action. Danny got out ahead, making it halfway up the stairs. Eric pivoted and fired his carbine rifle. A shot tore through Danny's left knee: in the front and out the back. He stumbled and began to fall. Eric fired again and again. As Danny collapsed, he took a second bullet to the chest, and a third to the abdomen. The upper round went straight through him as well, causing severe trauma to his heart. It stopped pumping immediately. The third shot lacerated his liver and stomach, causing major organ damage and lodging inside.

Lance tried to catch Danny, but realized he had been hit, too, multiple times, in the chest, leg, knee, and foot.

Danny's face hit the concrete sidewalk. Death was almost instantaneous.

Lance went down on the grass. He blacked out, but continued to breathe.

Sean burst out laughing. He was sure it was paintball. They were part of the game now.

Sean felt a shot zip by his neck. It left a cool breeze in its wake. He felt a couple of pricks, like an IV needle being pulled out. He did not realize he had been shot. He looked around. Both his friends were down. Pain signals reached Sean's brain. It felt like someone had kicked him in the back. He ran back for the door they had come out. He nearly made it. But the pain overcame him, his legs gave out, and he collapsed. He couldn't feel his legs anymore. He could not understand what had happened. He seemed to have been shot by a tranquilizer gun.

Eric turned again and spotted five kids under a clump of pines in the grass. He fired, and the kids took off running. One fell. He played dead, too. Another took a hit but kept on running. The last three got away clean.

The shooters kept moving. Lance regained consciousness. He felt someone hovering above him. He reached up toward the guy, tugged on his pant leg, and cried for help.

"Sure, I'll help," the gunman said.

The wait seemed like forever to Lance. He described the next event as a sonic blast that twisted his face apart. He watched chunks of it fly away. Breaths came rapidly: air in, blood out. He faded out again.

Dylan made his way down the hill, toward Sean. Several people in the cafeteria saw him coming. Someone ran out, grabbed Sean, and started dragging him in. An adult stopped him. She said it was dangerous to move a seriously injured person. Sean ended up propped in the entrance, with the door pressed against him. Someone tried to step over him on the way out, planted a foot into Sean's back, and said, "Oh, sorry, dude."

A janitor came by and reassured Sean. He held Sean's hand, said he would stay with him, but he had to help kids escape first. He advised Sean to play dead. Sean did.

Dylan fell for it again, or pretended to. He stepped right over Sean's crumpled body and walked inside.

A stampede was under way in there. The lunch crowd had panicked. Most took cover under tables; some ran for the stairs. Coach Sanders heard the commotion in the faculty lounge and ran toward the danger.

"I don't think he even thought about it," his daughter Angela said later. "His instinct was to save his kids."

Dave burst into the commons and tried to take charge. Two custodians followed him to assist. Sanders directed students to get down. He rethought that pretty quickly and yelled, "Run!"

Sanders looked around. There were exits in three directions, but most of them looked bad. There was one plausible option: across the commons and up the wide concrete stairway to the second floor. No telling what was up there, but anything was better than this. Sanders led the way. He ran across the open room unprotected, waving his arms to get the kids' attention and yelling for them to follow. The tables offered little true protection, but they felt felt a lot safer. It was scary out in the open. The kids trusted Coach Sanders, though. a lot safer. It was scary out in the open. The kids trusted Coach Sanders, though.

A wave of students swelled behind Sanders. Most of the 488 people in the commons followed him toward the stairs. He bolted to the top and spun around to direct traffic. To the left! To the left! To the left! To the left! He sent them all down the corridor toward the east exit, away from the senior parking lot. He sent them all down the corridor toward the east exit, away from the senior parking lot.