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 devastating to hear that phone call," JaMar Pittman, JaVon's father, told CNN. "You try to be there for your kids. You can't be there for your kids, and you get nervous. And for you to be their leader, their father, the superhero, whatever. You can't save your kids. That's devastating."

Tate Myre, one of the four students who died from his injuries, was described by JaVon as a "wonderful kid" who was probably one of the best people he had ever met. Sixteen-year-old Myre, who had played football for the school's varsity team since he was a freshman, was an honor student with "a bright future" and beloved by all, according to WKTV

But while reliving the terrifying moments of the Nov. 30 school shooting, Pittman learned that another classmate, Justin Shilling, had died. The high school senior broke down in his mother's arms, overcome with the news of losing another good friend. "Me and him used to laugh about everything. We were cool," JaVon said. Shilling, 17, died Wednesday morning, according to the Oakland County Sheriff's office. 

Ethan Crumbley, 15, was charged as an adult with terrorism causing death and four counts of first-degree murder. According to Oakland County Prosecutor Karen D. McDonald, he is also facing seven counts of assault with intent to murder and 12 counts of possession of a firearm during the commission of a felony.