He settled in Newtown eight years ago. His two oldest children, ages 13 and 14, had attended Sandy Hook.

"It's just horrific," Nikitchyuk said. "I don't know how our little ones are going to be affected by all this, but our older ones, I think, matured in just a few days."

The father was spurred to action: "This horrific event woke me up." He traveled to the White House to speak up for gun control. He was the Sandy Hook representative for a Newtown United delegation that was joined by families who had lost loved ones to gun violence in the mass shootings in Aurora, Colorado, Columbine and Virginia Tech, as well as random shootings in Chicago.

"I was the luckiest guy in the room because my kid survived and theirs didn't."

The group met with Valerie Jarrett, senior adviser to President Obama.

Nikitchyuk's message: "This is unacceptable in our society. We have to do better."

Emergency plans and instinct

Kindergarten teacher Janet Vollmer heard what she believed were gunshots. Then, the intercom system piped in the sounds of gunfire into her room. The teachers were well-schooled on drills; their principal made sure of that.

Vollmer immediately began putting her emergency planning to use. She knew the drill was to get kids outside and to the nearby firehouse. But it seemed too dangerous. She had 19 children she needed to protect.

"There was no announcement of what was going on," she said. "My instinct was it wasn't good."

The teacher of 18 years gathered her kindergartners in a cubby area away from the door. Teaching assistants closed the blinds.

"We read a story and we kept them calm," she said. "We do this as teachers. We are trained. We have drills. We talk to the kids and in case something were to happen, this is what we do."

After about 30 minutes, she said, police knocked on the door. The children were told to close their eyes and walk in a line outside. She told the kids to look straight at the walls and nothing else until they got outside. They headed to the Sandy Hook firehouse, the school's emergency gathering point.

It would be hours before she learned the awful magnitude. She had taught 10 of the slain children just last year.

'The gift of these children'

Gene Rosen's home sits right next to the firehouse. Inside his house, the kids continued to wail.

"We can't go back to school!"

At one point, one of the boys broke through his tears with a note of levity. He sat up, held his finger in the air and said, "Just saying, your house is very small."

"In that moment, he brought into the home peace and light," Rosen recalled. "I felt like an angel descended upon us and this boy, and we laughed."

"God sent a respite from hell -- just a moment of recess." He paused, then added: "They saw their teacher assassinated."