More than a dozen people, including elementary school children, were shot and killed at a Newtown, Conn., elementary school this morning, federal and state sources tell ABC News.

A shooting involving two gunmen erupted at a Connecticut 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.

It's unclear how many people have been shot, but more than a dozen people including school children are dead, multiple federal and state sources tell ABC News

[link to abcnews.go.com]