IRVING -- Fire crews are investigating what caused a large church fire in Irving that destroyed a sanctuary early Thursday morning.

Just after 6 a.m., firefighters were called to Bear Creek Community Church on Finley Road, just north of U.S. 183 between North Belt Line Road and North Story Road.

Heavy smoke and large flames were showing when they arrived.

No injuries have been reported.

Battalion Chief of the Irving Fire Department Rick Sanderson said 23 pieces of equipment and 40 firefighters were sent to fight the fire. The cause is still under investigation.

Sanderson said the sanctuary is probably a "total loss" after part of the roof collapsed. There's water and smoke damage in other parts of the building, he said.

Crews were in the "overhaul" stage looking for hot spots by 8 a.m.The pastor of the church, Dennis Webb, told WFAA that a firefighter friend called him at about 6 a.m. and told him there was a three-alarm fire at the church. As a retired firefighter, Webb said he knew it was bad and drove his truck up to the church."It's not anything that we want to wake up to," he said.He added that the most important thing is that no one was hurt or killed. He said the sanctuary, which was built in 1969, suffered the most damage. He believes most of the church is still in tact, though, and his congregation can still hold services.

Webb said the church lets the homeless stay inside its fellowship hall when the temperatures outside drop below 32 degrees. They were hosting about 10 to 12 people, who are now being helped by the Red Cross."We'll rebuild and we'll keep serving the Lord," he said. "You know, that building is not the church. That is the building that we use to worship in. The church is our members."