A man suffered life-threatening head injuries after a dumpster rolled down a ramp and hit him Friday afternoon.

Paramedics were called to the scene at 31 Princess St., near Sherbourne and Front Streets, shortly after 1:30 p.m., where they found the man bleeding and unconscious.

Firefighters from a station nearby said they ran to the scene when they heard the screams of a person who witnessed the incident.

The group of firefighters resuscitated the man using first aid before the ambulance arrived. The unidentified man was then taken to a nearby hospital for treatment.

Toronto Fire Capt. Bill Bygrave said the man is a 51-year-old part-time maintenance worker.

Police said that part of the incident was captured on video surveillance. Det. Steve Matthews said that the man appeared to be bringing a dumpster down a ramp to the garage of the building, and somehow lost control of the heavy bin.

"At some point he lost control of the dumpster and received life-threatening head injuries," Det. Steve Matthews told CTV Toronto.

"From the video, it appears (the dumpters) picked up speed and he lost control of it."

Police did not provide further details of the incident, but said that the Ministry of Labour would be participating in the investigation.