17-year-old JaVon Pittman, a student at Oxford High School, recalled calling his father in the frightening moments when his fellow classmate, Ethan Crumbley, 15, opened fire on the school, injuring seven students and killing four. Pittman recounted to CNN's Adrienne Broaddus how he took cover with his classmates, a safety procedure he was taught in school but never expected he'd to have to use. "We put the table at the door, barricaded the doors, and we just turned the lights off and we hid under the desk," Pittman told Broaddus. The high school senior went on to describe calling his father, telling him that there was an active shooter at his school. "I was whispering because I didn't want the shooter to hear me and my classmates. And my dad was just asking me what's going on — what's happening? And I told him there's a shooting — somebody's here shooting up the school." Pittman's younger brother, Jonte, was also at the school at the time of the shooting and escaped. "It was...