About 80 firefighters were called in to battle a massive blaze that caused extensive damage to six townhouse units in Bolton early Wednesday morning.

Of the six townhouses that sustained substantial damage, four are likely a total loss, meaning their occupants will be displaced for some time, said Caledon fire Chief Brad Bigrigg.

A seventh townhouse may have sustained water damage, said Ontario Provincial Police Const. Jonathan Beckett.

"Obviously, with the damage to these homes (residents) are going to be out of their homes for a long time," Beckett told CP24's Cam Woolley.

Everyone escaped without injury, police and fire officials said.

Several pets, including two cats, escaped with their owners or were rescued from the townhouses by emergency personnel.

Beckett said residents and pets displaced by the fire have found places to stay with family and friends.

Bigrigg told CP24 the residents were fleeing their homes, which had functioning smoke alarms, when fire crews arrived at the scene on Alderbrook Place at about 3:30 a.m.

Bigrigg said working smoke detectors alerted sleeping residents and allowed them to escape the burning homes. Neighbouring homes were evacuated as a precaution.

Jennifer Roy and her family were forced to flee their home when a police officer banged on the door and told them to get out.

"It's just very, very scary," Roy said of the situation as she cradled her young son in her arms. "As long as everybody is OK, that's all that really matters."

When they arrived, firefighters went into an immediate attack to prevent the blaze from spreading even further.

Shortly after 5 a.m., officials put out a call for more firefighters to attend the scene to provide relief and help crews to get control of the blaze. Firefighters on the west side of the complex pulled back because of fears a wall may collapse. Roofs of three townhouses partially collapsed. The fire was under control by about 6 a.m. and most firefighters had cleared the scene by 9 a.m.

Bigrigg said 75 volunteer firefighters and five full-time firefighters were brought in to battle the blaze.

The cause of the fire is under investigation, but investigators believe the blaze may have started on or near a back deck before it spread to one townhouse and then to others through attics. At least one person who lives on the street went door-to-door to alert people of the blaze.

Bolton is about 25 kilometres northwest of Toronto.

It has been a busy 24 hours for firefighters in southern Ontario.

In Point Edward near Sarnia, several apartments were damaged when fire ripped through a three-storey building.

Everyone was safely evacuated and there were no injuries.

It was also a busy Tuesday evening for firefighters in London, where four apartments were heavily damaged in a fire. No injuries were reported.

With files from CP24's Cam Woolley and The Canadian Press

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