MATTHEW COURTER/Sun-Gazette

Investigators continue to look into the cause of Thursday morning’s two-alarm blaze on Memorial Avenue that leveled a large garage and damaged the exteriors to three separate double homes.

Pulling out of fire headquarters on Walnut Street, city firefighters could see heavy black smoke in the sky coming from the fire.

When they arrived on the scene about 10:15 a.m., much of the garage, which was at the rear of 868-870 Memorial Ave., was engulfed in flames and had already partially collapsed, investigators said.

Radiant heat had already ignited the sidings of three duplexes at 868-870 Memorial Ave., 609-611 Second Ave. and 864-866 Memorial Ave.

The most seriously-damaged double was the duplex on Second Avenue, but investigators said there was no actual extension of fire to the property’s interior, just the outside.

Still, seven people were displaced and were assisted by the American Red Cross.

There were no reports of injuries in the fire, which took about 15 minutes to bring under control.

The identities of the property owners or residents were not released.