At least three families are homeless after an early morning fire broke out in a townhouse complex in Barrie.

Firefighters were called to Owen Street on Tuesday after flames were spotted on the roof of the complex at around 5:30 a.m.

Raymond Kerr, a resident of the complex, went door-to-door, knocking and ringing doorbells to alert his neighbours.

“I was screaming at the top of my lungs, we ran down we were hitting doorbells,” says Kerr. “Really anything because we knew people were sleeping right.”

Kerr and many other residents didn’t hear smoke alarms, as the fire spread across the roof.

Four units suffered significant smoke and water damage.  Investigators estimate the total damage is more than $500,000.

The Ontario Fire Marshal’s Office is on scene and will assist Barrie fire in determining a cause.

Fire officials wants to take a closer look at the smoke alarms in the building. They say it's possible that the smoke never reached the alarms because of where the fire was burning.

“The smoke alarms in this fire may not have necessarily rang in the origin of this fire which was in the roof area and it’s above the smoke alarms,” says Barrie fire prevention officer Carrie Clark-Weatherup.

As the day went on, residents were allowed back into their homes to gather medications and pets, but weren`t allowed to stay the night.

The Red Cross is paying for three nights of shelter at a local motel for anyone who needs it and the owners of the complex are collecting donations.

Those can be dropped off at Amanding Construction Ltd. located at 394 Tiffin Street.