Live updates:
http://abcnews.go.com/blogs/headlines/2012/12/live-updates-newtown-ct-school-shooting/
1:26 p.m.: President Obama has been briefed on shooting by FBI director Bob Mueller and spoken with Conn Gov. Dan Malloy.
1:17 p.m: One shooter is described as 24-years-old, armed with four weapons and wearing a bullet-proof vest, sources tell ABC News.
1:09 p.m.: Twenty-seven people, or more, most of them children killed in shooting, sources tell ABC News.
12:57 p.m.: Fatality numbers continue to rise. More than 25 people, mostly young children, killed in Newtown, Conn. school shooting, sources tell ABC News.
12:47 p.m.: More than 20 people, most of them young children, killed in elementary school shooting, according to law enforcement sources.
12:36 p.m.: Law enforcement conducting car to car searches in area of school.
12:26 p.m.: More than a dozen persons, including children shot and killed at Newtown, Conn., elementary school, federal, and state law enforcement sources tell ABC News.
12:24 p.m.: Law enforcement agents with weapons drawn seen running into wooded area behind the school.
12:19 p.m.: Federal agents are at the scene of the school with guns still drawn as parents rush to pick up their children.
State police personnel led children from the school, following a shooting at Sandy Hook Elementary.
12:11 p.m: LIVE streaming video from chopper above Sandy Hook Elementary.
12:09 p.m.: Sources tell ABC News multiple persons shot
11:55 a.m.: Danbury Mayor Mark Boughton tells WABC three victims in hospital are in very serious condition.
11:52 a.m.: Danbury Hospital confirms three patients have been taken there for treatment.
A shooting involving two gunmen erupted at a Connecticut elementary school this morning, prompting the town of Newtown to lock down all of its schools and draw SWAT teams to the school, authorities said today.
State Police confirm that one shooter is dead. A second gunman is apparently at large, sources told ABC News.
The shooting occurred at the Sandy Hook Elementary School in Newtown, about 12 miles east of Danbury.
State Police received the first 911 call at 9:41 a.m. and immediately began sending emergency units from the western part of the state. Initial 911 calls stated that multiple students were trapped in a classroom, possibly with a gunman, according to a Connecticut State Police source...............