Description: More than two dozen people, mostly elementary school children, were shot and killed at a Newtown, Conn., elementary school this morning, federal and state sources tell ABC News. The massacre involved two gunmen and prompted the town of Newtown to lock down all its schools and draw SWAT teams to the school, authorities said today. One shooter is dead and a manhunt is on for a second gunman. Police are searching cars. One shooter was described as a 24-year-old armed man with four weapons and wearing a bullet-proof vest, sources told ABC News.