Update 9:29 p.m.:
Police aren't say what may have motivated a man to open fire inside two classrooms at a Connecticut elementary school today, but a law enforcement official who has been briefed on the investigation says the gunman was believed to suffer from a personality disorder
Twenty-six people, including 20 children, were killed in the shooting rampage before the gunman shot and killed himself. Police say another adult was found dead at a second location.
A law enforcement official has identified the gunman as 20-year-old Adam Lanza, the son of a teacher at the Sandy Hook Elementary school. The official says Lanza killed his mother at their home before driving his mother's car to the school.
Police say the shootings took place in two classrooms, but they are not providing details on exactly how it unfolded.
Students and their parents describe teachers locking doors and ordering the children to huddle in classroom corners or hide in closets as shots echoed through the building. Authorities said the shootings took place in two nearby classrooms, but they gave no details on exactly how they unfolded.
NEWTOWN, Conn. -- Police say 27 people were killed in the shooting at a Connecticut elementary school, including the gunman, and one person died at another scene.
The dead at the school include 20 children.
The gunman opened fire Friday morning inside a school where his mother worked. He blasted his way through the building as young students cowered helplessly in classrooms while their teachers and classmates were shot.
The gunman killed himself. Gov. Dannel P. Malloy says someone who lived with him also died.
Young students crying and looking frightened were escorted by adults through a parking lot in a line after the shots rang out in Newtown, 60 miles northeast of New York City.
The attack comes less than two weeks before Christmas and appears to be the nation's second-deadliest school shooting, exceeded only by the Virginia Tech massacre in 2007.
WASHINGTON -- A law enforcement official says the suspect in the Connecticut school shootings is 20-year-old Adam Lanza, the son of a teacher at the school where the shootings occurred. A second law enforcement official says the boy's mother, Nancy Lanza, is presumed dead.
The first official says Adam Lanza's older brother, 24-year-old Ryan, of Hoboken, N.J., is being questioned by police. An earlier report from a law enforcement official mistakenly transposed the brothers' first names.
Both officials spoke on the condition of anonymity because they were not authorized to speak on the record about the developing criminal investigation.
The first official said Adam Lanza is dead from a self-inflicted gunshot wound.
WASHINGTON -- A tearful President Barack Obama says the country's leaders must "take meaningful action" regardless of politics in response to the mass shooting at a Connecticut elementary school.
The president teared up, at times using an index finger to wipe at the corner of his eyes, as he addressed the nation from the White House. He also paused repeatedly as he struggled to keep his composure while speaking of the children - ages 5 to 10 - who had died and the life milestones they now would miss.
He said, quote, "Our hearts are broken."
Shortly before speaking, Obama ordered that U.S. flags be flown at half-staff on public grounds through Tuesday.
Twenty children were killed Friday in a shooting at a Connecticut elementary school that left a total of 27 people dead, including the gunman, the police said.
Six adults were killed in the shooting at Sandy Hook Elementary School in Newtown, Connecticut State Police spokesman Lt. Paul Vance told reporters at an afternoon news conference. At least one teacher was wounded.
A source familiar with the investigation identified the shooter as 20-year-old Adam Lanza, CBS News investigative producer Pat Milton reports. Law enforcement sources had earlier told CBS News that the gunman was Ryan Lanza, Adam Lanza's older brother.
Ryan Lanza is being questioned by authorities in New Jersey, Milton reports.
Vance said police found the gunman deceased inside the school. He did not say how the shooter died.
A law enforcement official told CBS News that the gunman's mother worked at the school and is among the dead. The gunman apparently targeted his mother and her classroom, the official said. Most of the shooting occurred in that classroom. Some of her students were among those killed.
Separately, a dead body was found at a secondary crime scene in Newtown, Vance said.
Law enforcement sources told CBS News senior correspondent John Miller the gunman apparently drove to the school from New Jersey. A law enforcement official in Washington told The Associated Press that New Jersey State Police were searching a location in that state in connection with the shootings.
It is unclear if there was more than one gunman at the school. Miller reports authorities have an individual in custody who investigators said may be a possible second shooter.
CBS News correspondent Bob Orr reports that authorities found two guns on the gunman's body, a Glock 9 mm pistol and a Sig Sauer pistol. A Bushmaster assault rifle was found in his vehicle, Orr reports. The weapons appeared to be legally purchased, one source told Orr.
"Our hearts are broken today for the parents and grandparents, sisters and brothers of these little children and for the families of the adults who were lost," an emotional President Obama said Friday afternoon in a statement delivered from the White House briefing room. "Our hearts are broken for the parents of the survivors, as well. For, as blessed as they are to have their children home tonight, they know that their children's innocence has been torn away from them too early, and there are no words that will ease their pain."
White House spokesman Jay Carney said Mr. Obama was informed of the shooting at 10:30 a.m. ET by homeland security adviser John Brennan.
CBS Hartford affiliate WFSB-TV reports around 600 students attend the school.
A dispatcher at the Newtown Volunteer Ambulance Corps said a teacher had been shot in the foot and taken to Danbury Hospital.
An 8-year-old student told WCBS-TV he was on his way to the school's office when he saw the gunman.
"I saw some of the bullets going down the hall and then a teacher pulled me into her classroom," the boy said.
Stephen Delgiudice said his 8-year-old daughter heard two big bangs and teachers told her to get in a corner. His daughter was fine.
"It's alarming, especially in Newtown, Connecticut, which we always thought was the safest place in America," he said.
Delgiudice's daughter told him that she heard the loudspeaker come on and swearing being broadcast over it, Delgiudice told CBS News. That prompted the teacher to lock the classroom door.
"That's basically what saved their lives I think," Delgiudice told CBS News.
Lisa Bailey, a Newtown resident with three children in Newtown schools, told CBSNewYork.com, "Newtown is a quiet town. I'd never expect this to happen here. It's so scary. Your kids are not safe anywhere."
The superintendent's office said the district had locked down schools in Newtown, about 60 miles northeast of New York City. Schools in neighboring towns also were locked down as a precaution.
State police said Newtown police called them around 9:40 a.m.
A photo posted by The Newtown Bee newspaper showed a group of young students — some crying, others looking visibly frightened — being escorted by adults through a parking lot in a line, hands on each other's shoulders.
Students were taken to a nearby firehouse to be reunited with their parents, CBSNewYork.com reports.