BLACK CANYON CITY, Ariz. – A brush fire near Black Canyon City that broke out Saturday evening is now considered suspicious and is under investigation, according to the Daisy Mountain Fire Department.

Both Black Canyon and Daisy Mountain fire crews responded to a reported debris fire at a yard belonging to a towing company Saturday evening to find winds had moved the fire out of the yard, starting the brush fire.

Dubbed the "Joe Hill Fire," the fire spread overnight and led to 20 area residents being evacuated Sunday morning.

The evacuations were lifted 6 p.m. on Sunday.

The fire spread to be about 50 acres in size and as many as six structures have been lost, according to Daisy Mountain Fire Department.

The fire department said they are concerned about the potential hazardous materials in the junk yard and are working with the Arizona Department of Environmental Quality to determine if any hazardous material is involved.

The fire crews are working on reinforcing fire breaks to prevent the fire from spreading any more. They said there is a concern of potential high winds can push fire across the breaks.

So far, no injuries have been reported from the area residents or firefighters.

The investigation is ongoing.