A fire heavily damaged the attic of a church north of downtown early Sunday morning. 

Crews responded to a fire at the church in the 600 block of North Sixth Avenue, near East Sixth Street, after a passerby called 911 at 2 a.m., Capt. Barrett Baker, a spokesman for Tucson fire said in a news release. 

Firefighters saw heavy smoke coming from vents above the third floor of the church, the release said. 

Several engine companies responded to the two alarm fire and crews searched the church to see if anybody was inside and to locate the source of the fire. 

They determined the fire was coming from the attic and crews pulled down the ceiling using long poles and extinguished flames by spraying water into the holes. A ladder crew cut several holes in the roof to allow smoke to escape and sprayed water to knock down flames in the holes. 

It took 41 firefighters 20 minutes to extinguish the blaze. 

Nobody was injured. 

The cause of fire is still under investigation.