WATCH: CNN interviews ‘shaken up’ student in locked down classroom at Great Mills High School

Jonathan Freese, a student at Great Mills High School in St. Mary's County, Maryland, called in to CNN on Tuesday while he was still in lockdown amid an early morning shooting.

Talking with CNN host John Berman, Freese described the situation he'd experienced as he sat in his math class at the high school.

"At first I heard that a couple of people got shot at about 7 [a.m.] or so," he said. "One person is supposedly dead, what I've heard."

Freese, who said he was far away from the shooting when it occurred, said police were now going through the building room by room to ensure students' safety and he said that "soon we are going to be escorted out of the school."

Freese said that he has done active shooter drills at the schools "a couple of times," though he still never expected anything like this to happen. He also praised police for their fast response to the shooting.

Watch the video below.