Teacher barricades himself in class, fires gun; no one hurt

People lineup inside the Dalton Convention Center to pick up their children on Wednesday, Feb. 28, 2018 in Dalton, Ga. (C.B. Schmelter/Chattanooga Times Free Press via AP)

ATLANTA (AP) — A social studies teacher barricaded himself inside a classroom at a Georgia high school on Wednesday and fired a handgun, sending students running outside or hunkering down in darkened gym locker rooms, authorities said.