"He said he heard a lot of loud noises and then screaming," said his mother, Melissa Makris. "Then the gym teachers immediately gathered the children in a corner and kept them safe."
Another girl who was in the gym recalled hearing "like, seven loud booms."
"The gym teacher told us to go in a corner, so we all huddled and I kept hearing these booming noises," the girl, who was not identified by name, told NBC News. "We all started — well, we didn't scream. We started crying, so all the gym teachers told us to go into the office where no one could find us."
An 8-year-old boy described how a teacher saved him.
"I saw some of the bullets going past the hall that I was right next to, and then a teacher pulled me into her classroom," said the boy, who was not identified by CBSNews.com.
Robert Licata said his 6-year-old son was in class when the gunman burst in and shot the teacher. "That's when my son grabbed a bunch of his friends and ran out the door," he said. "He was very brave. He waited for his friends."
He said the shooter didn't utter a word.
"The shooting appears to have stopped," the dispatcher radioed at 9:38 a.m., according to the Post. "There is silence at this time. The school is in lockdown."
And at 9:46 a.m., an anguished voice from the school: "I've got bodies here. Need ambulances."
A half mile away, nurse Maureen Kerins was loading a broken chair into her car at about 9:45 when her cell phone rang. A friend wanted to know if her children were safe. There had been shooting at the elementary. Kerins' five kids are older, but she jumped in her car and raced to Sandy Hook. When she told police she was a nurse, they let her through.
As she approached the school, teachers were leading their children out single file, each had their hand on another's shoulder.
"It was very orderly. They weren't even running, they were just walking, following their teacher," she said. "Nobody was screaming. Parents were racing around looking for their kids, but the kids were just in line, following their teacher. Some were crying, but mostly they were calm."
She made a couple more trips with children, then went back to the school and waited with another nurse and a pediatrician to help treat the wounded. None ever came out.
"You expected them to be bringing out more kids," said Debbie Leidlein, the school board president, who was home sick but rushed to the school when she heard the news, "and it just wasn't happening."
Kerins waited for two hours, watching as police officers came and went but never brought any more children outside.
"Finally they said to us they didn't need us anymore. We knew it was bad."
Carefully, police searched room to room, removing children and staff from harm's way. They found Adam Lanza, dead by his own hand after shooting up two classrooms. No officer fired a gun.
Student Brendan Murray told WABC-TV it was chaos in his classroom at first after he heard loud bangs and screaming. A police officer came in and asked, "Is he in here?" and then ran out.
"Then our teacher, somebody, yelled, 'Get to a safe place.' Then we went to a closet in the gym and we sat there for a little while, and then the police were, like, knocking on the door and they were, like, 'We're evacuating people, we're evacuating people,' so we ran out."
As they were led away, children were warned to close their eyes so they would not see the gruesome aftermath of the attack.
Parents rushed to the scene. Family members walked away from a firehouse that was being used as a staging area, some of them weeping. One man put his arms around a woman as they walked down the middle of the street, oblivious to everything around them.
Gov. Dannel P. Malloy and other public officials came to the firehouse. So did clergymen like Monsignor Robert Weiss of Newtown's St. Rose Roman Catholic Church. He watched as parents came to realize that they would never see their children alive again.
"All of them were hoping their child would be found OK. But when they gave out the actual death toll, they realized their child was gone," Weiss said.
He recalled the reaction of the brother of one of the victims.
"They told a little boy it was his sister who passed on," Weiss said. "The boy's response was, 'I'm not going to have anyone to play with.'"
Long into the night, Leidlein sat with parents who had lost their children, trying to do what little she could to offer consolation.
"They were asking why. They can't wrap their minds around it. Why? What's going on?," she said. "And we just don't have any answers for them."
Associated Press writers Jim Fitzgerald, Matt Apuzzo and John Christoffersen in Newtown, Jocelyn Noveck in New York and Bridget Murphy in Boston contributed to this report.