Investigators are trying to figure out how a half-naked man came to be trapped on the roof of a boarded-up bungalow at 427 Avenue G South that was burning from the inside.

Police, fire trucks and ambulances responded at about 10:00 a.m. CST. 

Fire crews arrived to find smoke seeping from eaves, and the man on the roof. They used a ladder to help get the man down. He was then handcuffed and placed in a cruiser.

Fire fighters then used axes to knock open the front door. They had the fire under control in minutes.

There's no word yet on how it started.

Neighbours said they heard a commotion from the backyard before the man appeared on the roof. They didn't how he got up there.

The house was unoccupied.