Mourners gather inside the St. Rose of Lima Roman Catholic Church at a vigil service for victims of the Sandy Hook School shooting December 14, 2012 in Newtown, Connecticut. Twenty-seven people are dead, including 20 children, after a gunman identified as Adam Lanza in news reports opened fire in the school. Lanza also reportedly died at the scene. (Photo by Andrew Gombert-Pool/Getty Images)
Laura Petrecca, USA TODAY
SANDY HOOK, Conn. -- A day after a small New England town was rocked by unimaginable violence, a community is left shattered, and a nation is left reeling.
Officials scheduled a news conference for Saturday morning. Investigators and the medical examiner worked through the night to identify the dead and hoped to release names today.
On Friday, 20-year-old Adam Lanza entered Sandy Hook Elementary School in Newtown, Conn., where he shot and killed 20 young children, along with 6 of their teachers and caretakers. Police say Lanza's mother, who reportedly taught at the school, was killed earlier in the day.
Lanza was found dead inside the school of a self-inflicted gunshot wound.
At church vigils Friday night and gatherings all around Newtown into the wee hours of Saturday morning there was a collective cry of unbelief and grieving and people asking why and how something like this could have happened.
The unsatisfying answer is that nobody knows why Adam Lanza shot his mother and why he then took her guns to the school and murdered 26 others.
Around town flags flew at half mast. On Church Hill Road, which leads into Sandy Hook, a large sheet hung on the side of a bridge. The blue lettering read: "We (heart) you Sandy Hook Elementary."
Declan Procaccini said Saturday he was bracing himself for the release of the names of those who died.
"It's just something that right now I can't even imagine when they release the names of those children," he told CNN.
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He said his daughter was in a reading class with other children and two teachers when the shooting started. They locked themselves in a bathroom until police banged on the door and led them through the school -- and the bloody scene -- to safety.
What happened on Friday "is lunacy," said local resident Shannon Doherty. "It's nuts, it's totally nuts."
The town is so close that he is sure he's going to know the victims. "We're going to know these kids," he said.
He and his wife Tamara aren't sure what to say to their own kids, a 10-year-old boy and a 13-year-old girl, about the terrible events. "What do you tell them?" he asked.
After receiving word of the shooting, Tracy Hoekenga who was at one vigil she was paralyzed with fear for her two boys, fourth-grader C.J. and second grader Matthew.
"I couldn't breathe. It's indescribable. For a half an hour, 45 minutes, I had no idea if my kids were OK," she said.
The nightmare began on Friday when Adam Lanza drove his mother's car through a 300-year-old town with its fine old churches and towering trees and arrived at a school full of the season's joy. Somehow, he got past a security door to a place where children should have been safe from harm.
Sandy Hook Elementary School teacher Theodore Varga and other fourth-grade instructors were meeting; the glow remained from the previous night's fourth-grade concert.
"It was a lovely day," Varga said. "Everybody was joyful and cheerful. We were ending the week on a high note."
And then, suddenly and unfathomably, gunshots rang out. "I can't even remember how many," he said.
The incident -- among the worst school shootings in U.S. history -- is the latest in a series of mass shootings in the U.S. this year, including Tuesday's assault by a lone gunman at a Portland, Ore., shopping mall that left two dead and one wounded.
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Three weapons were found at the scene in Newtown - a Glock and a Sig Sauer, both pistols, inside the school, and a .223-caliber rifle in the back of a car.
A federal law enforcement official said the guns had been legally bought and registered by the shooter's 52-year-old mother, Nancy Lanza, USA TODAY's Kevin Johnson reported.
As the Newtown community struggles to cope with the unspeakable violence that claimed 20 of their youngest members, new details about Adam Lanza are beginning to emerge.
Ryan Lanza, the suspect's 24-year-old brother, who was questioned by law enforcement in Hoboken, N.J., on Friday, said Adam was believed to suffer from a personality disorder. He told police that he had not been in touch with his brother since about 2010.
Restaurant owner Mark Tambascio, a family friend, said Nancy Lanza told him recently that her son Adam had Asperger syndrome, that he was "getting out of control and that she might need special help for him."
Adam Lanza's aunt said her nephew was raised by kind, nurturing parents who would not have hesitated to seek mental help for him if he needed it, the Associated Press reported.
Marsha Lanza, of Crystal Lake, Ill., told AP she was close with Nancy Lanza, and sent her a message on Facebook on Friday morning asking how she was doing. Nancy Lanza never responded.
Marsha Lanza described Nancy Lanza as a good mother and kind-hearted.
If her son had needed counseling, "Nancy wasn't one to deny reality," she said.
Marsha Lanza said her husband saw Adam as recently as June and recalled nothing out of the ordinary about him.
Investigators are trying to learn as much as possible about Adam Lanza. So far, authorities have not spoken publicly of any possible motive. They found no note or manifesto, and Lanza had no criminal history.
Witnesses told AP that during the shooting, Lanza didn't utter a word.
Police said the shootings took place in two rooms in one section of the school building, including a kindergarten classroom.
Varga said he was a meeting with other teachers when he heard the gunfire, but there was no lock on the door.
He said someone turned on the public address system so that "you could hear the hysteria that was going on. I think whoever did that saved a lot of people. Everyone in the school was listening to the terror that was transpiring."
As the shooting erupted, quick-thinking teachers and faculty members hid some students in closets and bathrooms, while others rounded up students and spirited them out of the building.
Children lucky enough to escape the carnage fled in frightened groups -- some crying, some holding hands -- as they were escorted from the single-story school by teachers. Witnesses reported up to 100 shots were fired.
State Police Lt. Paul Vance said the murder scene was so gruesome that first responders, including tactical squad police, were provided counseling later in the day. "This was a tragic, horrific scene they encountered,'' he said.
Vance said 18 of the children and six adults died at the school. Two other children were pronounced dead after they were taken to local hospitals. One wounded victim was hospitalized.
In Washington on Friday, a visibly shaken President Obama, wiping away tears, said he was "heartbroken."
"These were "beautiful little kids between the ages of 5 and 10 years old,'' Obama said. "They had their entire lives ahead of them. Birthdays. Graduations. Weddings. Kids of their own."
Sandy Hook is in a residential, wooded neighborhood about 60 miles northeast of New York City. The school, which serves kindergartners to fourth-graders, has 39 teachers and nearly 700 students. A reverse 911 call went out to parents warning of an incident, shaking the quiet, middle and upper-middle class community of 27,000 to its core.
"This is the most tragic thing we've ever encountered,'' said Newtown Police Lt. George Sinko. "We have to think about the families right now."
Sandy Hook Elementary Principal Dawn Hochsprung is one of the victims who died, said Gerald Stomski, first selectman of Woodbury, Conn. He said police told him Hochsprung died in the attack.
He says she was a principal in Woodbury until a few years ago. He says residents were mourning her death.
Stomski says she had "an extremely likable style."
Hochsprung had been principal at Sandy Hook Elementary since 2010. Hochsprung had frequently tweeted photos from her job and wrote upbeat tweets about what was going on at the school.
More hauntingly, several publications report she wrote a letter before the school year outlining new safety measures including locked doors during school hours.
Hundreds of Newtown resident met Friday night in three different churches to remember the victims, offering hugs, tears and words of kindness to their fellow townspeople.
Hundreds packed the St. Rose of Lima church in Newtown, while hundreds more spilled outside. Some held hands in circles and offered prayers. Others lit candles and sang Silent Night.
On Friday evening, Ray Ruzek, owner of Heaven ice cream shop in Sandy Hook, attached a handwritten sign next to store sign posted outside his business. It said "Come pray 7 pm."
He has hosted a Christian prayer group at the shop on Friday nights since October, but he doesn't usually hang such a sign. But last night was different.
He knew others in the community would need additional support in the wake of a local shooting. And he wanted to make sure that his friends and neighbors knew that his group could be a resource for them.
"Tonight is obviously special to us because of the tragedy," he said.
Contributing: Carolyn Pesce, Gary Stoller, Gary Strauss and Doug Stanglin; Associated Press