Firefighters prevented a basement blaze from spreading to the rest of an East Brady Street house this morning.

Captain Tom Fair of the Butler Fire Department said the cause of the fire is being determined.

“It’s under investigation,” he said. “It’s suspicious.”

Fair said a state police fire marshal was contacted.

A family comprised of a couple and two young children were in an upstairs apartment of the house at 332 E. Brady St. when smoke filled the building. They subsequently evacuated.

The names of the family and the building owner were unavailable.

The fire was reported in a 6:22 a.m. 911 call.

“The fire was rolling across the basement ceiling,” Fair said.

He said the rest of the building only sustained smoke damage.

The VA Butler Healthcare Fire Department assisted Butler.

The American Red Cross was contacted to find housing for the displaced family.