A young man is recovering after falling about 10 metres down a chimney at a Mississauga high school early Thursday morning.

The 20-year-old man became trapped in the chimney at Gordon Graydon Memorial Secondary School at about 2:10 a.m. and had to be rescued by firefighters.

He suffered two broken ankles in the fall, Peel Regional Police said.

The high-angle rescue, involving a ladder truck and a rope system, took about two hours to complete. Firefighters had to dismantle part of the chimney's base to free the man.

Police said a group of young people was on top of the roof of the school, located at 1490 Ogden Ave. near the QEW and Cawthra Road, when the man plunged down the chimney.

Police haven't said why the group was on top of the school, but have charged the man and his five friends with trespassing.