Update: 4:15 PM
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.
Update: 3:55 PM
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.
Update: 3:25 PM
-- 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.
Update: 3:05 PM
A law enforcement official says the suspect in the Connecticut school shootings is 24-year-old Ryan Lanza and that his younger brother is being held for questioning as a possible second shooter. The law enforcement official says the boys' mother, Nancy Lanza, works at the school as a teacher.
The official also said Ryan Lanza's girlfriend and another friend are missing in New Jersey.
Speaking on condition of anonymity, the official said the suspect is dead from a self-inflicted gunshot wound.
The official spoke on the condition of anonymity because the source was not authorized to speak on the record about the developing criminal investigation.
Update: 1:50 PM
Family members are relaying what children told them about the shooting at Sandy Hook Elementary School in Newtown, Connecticut.
Stephen Delgiadice says his 8-year-old daughter heard two big bangs and teachers told her to get in a corner. His daughter is fine.
He says the shooting is alarming because his family always considered Newtown to be the safest place in America.
Seventeen-year-old Mergim Bajraliu heard the gunshots echo from his home and raced to check on his 9-year-old sister at the school. He says his sister heard a scream come over the intercom at one point. And he says teachers were shaking and crying as they came out of the building.
Update: 1:24 PM
A law enforcement official says the attacker in the Connecticut school shootings is a 20-year-old man with ties to the school.
The official said that a gun used in the attacks is a .223-caliber rifle. The official also said that New Jersey state police are searching a location in that state in connection with the shootings, said by an official in Connecticut to have left 27 dead, including 18 children.
The official in Washington spoke on the condition of anonymity because the source was not authorized to speak on the record about the developing criminal investigation.
Update: 12:56 PM
Official with knowledge of Conn. school shooting: 27 dead, including 18 children.
An official with knowledge of the situation says a gunman at the center of a school shooting in Newtown, Conn., has been killed.
The official who spoke on condition of anonymity because the investigation is still under way says the man apparently had two guns.
A dispatcher at the Newtown Volunteer Ambulance Corps says a teacher has been shot in the foot and taken to Danbury Hospital, but it's unclear whether there are other injuries.
Ambulance surrounded Sandy Hook Elementary School in western Connecticut and parents were running toward the building as a helicopter flew overhead.
The superintendent's office says the district has locked down schools.
State police say Newtown police called them at about 9:40 a.m. about the shooting reports.
Connecticut State Police say they are assisting local police in Newtown amid reports of a shooting at an elementary school.
The school superintendent's office says the district has locked down schools to ensure the safety of students and staff.
The shooting was reported at Sandy Hook Elementary School in Newtown, in western Connecticut. State police say Newtown police called them at about 9:40 a.m. about the reports.
The Newtown Bee posted a photo of 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.
State police spokesman Lt. Paul Vance says they have a number of personnel on the scene to assist.