A 55-year-old man died after he was crushed by a massive construction drill that toppled over Tuesday night in University City, police said.

Firefighters and police responded just after 9:10 p.m. to the 3100 block of Convention Avenue near Franklin Field and the Penn Museum and found the man trapped for an unknown amount of time under the drilling rig, police said.

The man, who was still breathing but unconscious and bleeding heavily, was rescued and transported by medics to Penn Presbyterian Medical Center, where he was pronounced dead at 9:45 p.m., said Chief Inspector Scott Small.

The rig was marked as belonging to Cook Drilling Corp. of Trevose. The company’s website show’s a rig that appears similar and says it weighs 75 tons.

The company’s website also lists a project related to the University of Pennsylvania among its active worksites.

A representative for the company could not be reached for comment.

The rig operator was not seriously hurt but may have been taken to the hospital to be checked out, Small said.

The cause of the incident was under investigation by police. The federal Occupational Safety and Health Administration also was expected to investigate, Small said.