Updated Tuesday, December 18, 2012 at 02:50 PM
The second graders had just finished their yoga poses and jumping jacks when the gunshots began.
Their teacher, Carol Wexler, herded the children — 18 of them — into a corner of the room, near their coat hooks, away from the hallway and the spasm of violence there.
She hurried back to the classroom door but was unable to lock it. She shut off the lights.
She had been trained for an emergency. Yet had she known the truth, she may well have frozen in fear.
The principal and the school psychologist lay dead in the corridor, killed by bullets fired by Adam Lanza, a troubled 20-year-old who lived nearby.
He had entered a classroom filled with first graders and opened fire. And then he began heading to other rooms. Wexler's was just across the hall.
The first accounts of the massacre at the school in Newtown, Conn., were terrifying: 26 dead, including 20 young children. But new disclosures about how much ammunition Lanza was carrying have cast Friday's events in an even grimmer light. The authorities said Sunday that he had hundreds of unspent rounds, raising the prospect that if he had not killed himself as the police approached, the number of victims could have been far higher.
The scene inside Sandy Hook Elementary School after Lanza began firing with a Bushmaster semiautomatic rifle was pieced together from numerous interviews with school officials, the police and parents.
In the second-grade classroom, Wexler, 52, raced back to her pupils.
She told them that they should all be very quiet, and to keep looking at her.
Some of the children reached into their backpacks for objects that brought them comfort — dolls, stuffed animals, worn blankets — which Wexler always encouraged them to bring to school.
"They were just hoping and praying no one would come through that door," said Heidi Werner, whose daughter, Grace, was in the class.
The children hid on the floor, amid their puffy winter jackets. One girl cried, and Wexler held her in her lap.
In an office, someone had flipped on the main control for the intercom, and disturbing sounds were coming from it.
Wexler, who spent 20 years in corporate finance before turning to teaching, began to sing holiday songs in a whisper.
The children whispered along.
"Jingle Bells." "Silent Night." "I Have a Little Dreidel."
They did not pause when they heard shots or screams.
In a nearby classroom, Lauren Rousseau, 30, was a substitute teacher who had begun working full-time only recently.
Lanza killed her, along with another teacher, and all of the children.
Everyone in the room was shot multiple times, authorities said.
Victoria Soto's class was next door.
Soto, 27, was youthful, energetic and a favorite among first graders. Her daily "morning meeting" with her children had just ended.
What happened next has been retold from the mouths of 6-year-olds, imperfect in their precise detail.
Children thought the gunshot sounds over the intercom were hammers falling or pots and pans clanging. One boy said he saw bullets flying past in the hallway.
Some said Soto rushed children into closets and cupboards. Others described a more chaotic scene of terrified children huddled along the far wall.
Soto slammed the door shut, but it was no obstacle.
Aidan, a 6-year-old boy, told his mother everything later.
"He said the gunman burst into the room," said his mother, Diane Licata. "He shot Ms. Soto and then began shooting the children."
Aidan was screaming.
"He was running around, as were many of the children," his mother said.
Some dashed behind the gunman, lunging for the door.
"They just ran," Diane Licata said.
Before reaching the hallway, Aidan paused to hold the door for his friend Emma.
In another classroom, a music teacher herded the children into a closet filled with instruments. To occupy their hands, she gave them lollipops.
All around the school, teachers were desperately trying to hide and soothe children.
A teacher read a story in a kindergarten class.
A librarian pulled out crayons and paper and told pupils, "Our job is just to be quiet."
In an art classroom, the door would not shut, so the teacher rushed the children into a small office. One girl, 9-year-old Vanessa Bajraliu, thought a wild animal was inside the building.
"Like a deer," she said later.
But she heard screaming on the intercom, and gunshots, and became afraid.
She sat on the floor in silence.
"I was just thinking," she said.
As for the other children, "They were just leaning on each other," Vanessa said. "They were whispering about, 'I wonder who it is,' or, 'I wonder if somebody got killed.'"
Their teacher taped over the door's clear windows with pictures and drawings. They waited.
The police arrived.
The school's front windows were shattered. Officers approached a conference room, guns drawn, and told the handful of adults who had gathered there for a parent-teacher conference to stay put. One woman had been shot and wounded. Paramedics wheeled her out on an office chair.
The last gunshot already had been fired. Lanza was dead by his own hand.
"We have a suspect down," a police officer, his voice cracking, said over the radio.
He struggled to catch his breath.
"Be advised. ... be advised we do have multiple weapons, including one rifle and one shotgun."
His voice cracked again.
"Be advised, we need buses here ASAP," he said, referring to ambulances. "Call Danbury if you have to."
Across the school, students stayed huddled in their classrooms, fearful that the gunfire would resume.
Someone banged on the classroom doors: "Newtown police!"
In one room, a teacher refused to open the door, unsure whether the siege was over. The police pushed it open.
Run outside, the officer said, and keep your eyes shut.
With their hands on the shoulders of the children in front of them, the children hurried past bodies and pools of blood, but it was hard to run with their eyes closed.
Vanessa said she opened hers once.
"Police," she said, describing what she saw.
Other children saw more. They later asked their parents why some of the children sprawled on the floor looked that way.
A 9-year-old girl in the fourth grade named Emma, when she got home that day, marched straight to her room with a friend, and emerged with a handwritten account of everything she had witnessed.
Her mother did not get past the title before breaking down.
It read, "The Shooting."
SHANNON HICKS / AP
Connecticut State Police lead a line of children from the Sandy Hook Elementary School in Newtown, Conn. on Friday, Dec. 14, 2012 after a shooting at the school.