A house under construction partially collapsed early Friday morning after a fire broke out in the garage and quickly spread to a neighbouring home.

Emergency crews were called shortly after 3:30 a.m. about a fire in the garage of 57 Westbourne Avenue, near Victoria Park Avenue and St. Clair Avenue East. The blaze quickly spread through the first home and then to a second home next door.

Both homes were under construction and were vacant, Toronto Fire Capt. Karen Reid told CBC Toronto.

Firefighters knocked down the blaze by 4:30 a.m., Reid said, but continued to look for hot spots in the roof.

Part of the back of the first home also collapsed, she said.

No injuries were reported. Reid later told CBC Toronto that a fire investigator is at the scene probing the cause of the blaze to determine whether or not to consider it suspicious. Toronto police were also on scene, canvassing the neighbourhood for information, according to Const. Alex Li, a spokesperson for the force.