An Ohio State University student was killed after he was pinned by an elevator, authorities said.

Andrew Polakowski, 18, of Erie, Pa., was the last person in a group of students to enter the elevator on the third floor about 11:30 p.m. Friday when it unexpectedly began to descend with the doors open, said Rick Amweg, assistant chief of the campus police.

Polakowski, a freshman pre-business major, was pinned when he tried to escape through a gap between the top of the elevator and the third floor, police said.

It was unclear if he jumped or tried to climb out, Amweg said. It also wasn't clear why the elevator descended with the doors open. Students gave differing accounts of how many people were inside.

Polakowski had chest and abdominal injuries, and he died of mechanical asphyxia, said Franklin County Coroner Dr. Bradley Lewis. The student was dead at the scene, Lewis said.

The dormitory, Stradley Hall, has 11 floors and about 400 residents, Amweg said.