WASHINGTON (AP) — One by one, behind closed doors, military officers explained what they did and didn’t do the night the U.S. diplomatic post in Benghazi, Libya, burned.

Together their 30 hours of testimony to congressional investigators gives the fullest account yet of the military’s response to the surprise attacks that killed the U.S. ambassador and three other Americans the night of Sept. 11, 2012, and early the next morning.