During the last night of the trip, staff members convinced the 69 students that there was a gunman on the loose. They were told to lie on the floor or hide underneath tables and stay quiet. A teacher, disguised in a hooded sweat shirt, even pulled on a locked door.

After the lights went out, about 20 kids started to cry, 11-year-old Shay Naylor said.

"I was like, ‘Oh My God,’ " she said. "At first I thought I was going to die. We flipped out."