Fire investigators are probing the cause of a massive three-alarm blaze that destroyed one home and damaged several others in Midtown early Thursday morning.

Bright orange flames were shooting several metres into the air as firefighters battled the blaze at a home that was being renovated on St. Clements Avenue. The flames and orange glow were visible from kilometres away.

Explosions, believed to be propane tanks stored at the home, were reported shortly before the house went up in flames.

Toronto police are also involved in the investigation. Officers are hoping to learn more from surveillance footage that was obtained from a person who lives in the area.

The house, between Caldow and Castlefield roads, was engulfed in flames when firefighters arrived at about 2:30 a.m. and is a total loss.

No injuries were reported.

The fire was so large and intense that neighbouring houses also sustained significant damage. One had its roof collapse, while another has holes in its roof. The blaze showered other nearby homes with hot embers, causing minor damage.

Witnesses estimated the flames extended about 15 to 30 metres into the air at the fire's peak, resulting in several homes being evacuated.

'Two huge explosions'

One of those evacuees, Angus MacDonald, was awakened by the fire's crackling sound at about 2:15 a.m.

"There were two huge explosions and then the fire just went right up," MacDonald told CP24 at the scene. "It was a huge ball of fire. We immediately got a few clothes on and ran out."

MacDonald said his wife grabbed a hose and sprayed water on their house in an attempt to protect it from the embers that were drifting onto their deck and roof.

Fire crews arrived minutes later and ordered them to clear the area for safety reasons. MacDonald said he moved his car to a safe spot because he worried it would be damaged by the fire's sparks.

A TTC bus was brought in to temporarily provide shelter to MacDonald and others who were forced from their homes.

MacDonald said he spent about two hours on the bus before he was allowed to return home.

"It was nice and warm and they looked after us," he said.

Workers devastated

Construction workers who were almost finished restoring the home told CP24 that they are devastated by the blaze.

They aren't sure what caused the fire. They said no portable heaters were in use and the natural gas and electrical services weren't active.

The only source of power was an electrical cord that was plugged in at a neighbour's house, they said.

The workers said nothing was amiss when they left the site Wednesday at 7 p.m. after finishing their shift.

Firefighters eventually brought the blaze under control and stayed on scene for several hours to monitor and douse hot spots that were still smouldering.

A damage estimate wasn't immediately available.

With a report from CP24's Cam Woolley