CBS is reporting that 27 people have been killed by a lone gunman at an elementary school in Connecticut:

CBS News is reporting that 27 people are dead, including 14 students, after a shooting at the Sandy Hook Elementary School in Newtown. The gunman is among the dead. CBS News’ John Miller reports there is preliminary information that the gunman was the father of one of the students. Miller additionally reports the gunman is 20 years old and is from New Jersey. The shooter was killed and apparently had two guns, a person with knowledge of the shooting said. The person spoke on condition of anonymity because the investigation was still under way. It is not known whether the shooter took his own life or was killed.

Updates to follow.

Update: An interview with one of the students on the scene:

Update: Fox is confirming that at least 26 people have been killed:

DEVELOPING: Authorities say at least 26 people, including 18 children, were killed Friday when a gunman opened fire inside a Connecticut elementary school. A law enforcement official said the shooter, who is dead, is believed to be a father of one of the students at Sandy Hook Elementary School in Newtown. An official with knowledge of the situation told the Associated Press that the man apparently had two guns. Earlier reports of a second gunman are unconfirmed. The Connecticut Post reports that police are also questioning a handcuffed man in connection with the shooting. Witnesses told the newspaper he was led out of the woods by officers.

Update: While it appears that one gunman is dead, there are more unconfirmed reports of a possible second gunman:

Police report that the school is now cleared of shooters, but they are still treating it as an active shooter situation and all schools in the district remain locked down. There are unconfirmed reports of a second shooter, but it is unclear what happened to that gunman. State police officers have gone classroom to classroom to make sure the school is clear. Authorities are searching the area, doing roadblocks and checking suspicious vehicles out of an abundance of caution. There are also unconfirmed reports that authorities have surrounded a purple van in Danbury that may be connected to the shooting. … The first 911 call reportedly came in just after 9:40 a.m., stating that multiple students were trapped in a classroom with a gunman, who authorities say was an adult who had at least two guns. The school locks its exterior doors during the school day, so it is unclear how the gunman or gunmen gained access to the building.

Update: From the White House:

“There is — will be, rather — a day for discussion of the usual Washington policy debates but I don’t think that day is today,” Carney said, noting also that President Obama believes that “it’s important on a day like to day to . . . feel enormous sympathy for families that are affected and to do everything we can to support state and local law enforcement and to support those who are enduring what appears to be a very tragic event.”

Update:

Update (MKH):

Local law enforcement held a press conference around 1:45 p.m., with a spokesman for Gov. Malloy and a Lt. Paul Vance in the state police force. There wasn’t much that we don’t already know, but there’s a bit about the timeline of the day.

Newtown Police received the 911 call at 9:30 a.m. They contacted state police and requested assistance from state police and surrounding police forces.

Police entered the school immediately upon arrival and conducted an active shooter search, which means “every door, every crack, every crevice, every portion of that school” was searched, Vance said.

“There were several fatalities at the scene, both students and staff,” Vance said, but said no specific information was being given out until all notifications were made.

“The shooter is deceased inside the building,” Vance said. “The scene is secure.”

Vance said there’s a great deal of search warrant activity going on, and many agencies are working on answering the many questions in this horrific incident.