Firefighters are still at the scene of house fire in Kitchener.

The fire broke out early Friday morning at the home on King Street East, between Sheldon Avenue North and Sydney Street North.

A family of five, and a resident in the upstairs unit, were alerted by the fire alarms and escaped unharmed.

One person received medical treatment at the scene as a precaution.

Crews worked to contain the flames so they wouldn’t spread to the neighbouring buildings.

They were still battling hot spots at 7 a.m.

Police say the damage is extensive.

“It’s pretty heavily damaged,” says Rick Brooks of the Kitchener Fire Department. “When you go up on the aerial and look down, a lot of the roof has been destroyed so you can see right into the building. Smoke alarms may have saved lives here.”

Officials say the house is not structurally sound.

The cause of the fire is still under investigation but they believe it started on in a washroom on the main floor.

King Street East, between Ottawa Street and Preston Street, remains closed to traffic.