A fire that broke out Friday at the First Baptist Dallas church, a landmark in the city’s downtown, appeared to cause major damage to an old part of the church complex.

The church’s pastor, the Rev. Robert Jeffress, said that he understood from his conversations with fire officials that in the fire’s final phase, the roof of what is known as the historic sanctuary had collapsed.

“We will have to see about whether we try to recreate it or do something else,” he said in an interview.

Dallas Fire-Rescue did not immediately provide information about the fire, but a spokesman told The Dallas Morning news that part of the structure had collapsed.

Gavin Nicholson, who lives in a high-rise apartment complex that overlooks the church complex, confirmed that it looked like a roof collapse; he could see flames coming from the center of the building.

“A piece of Dallas history is gone,” said Mr. Nicholson, who is the chief of staff for Venton Jones, a state representative whose district includes a portion of the city.