CHARLESTON, S.C. (AP) – Nine firefighters died in a blaze that swept through a furniture warehouse in a disaster the mayor described Tuesday as “difficult to fathom or quantify.”

“Nine brave, heroic, courageous firefighters of the city of Charleston have perished fighting fire in a most courageous and fearless manner, carrying out their duties,” Charleston Mayor Joseph P. Riley said at a morning news conference. “To all of their loved ones, our heart goes out to them.”

Overnight, firefighters saluted as the bodies of their colleagues were taken from the warehouse.

Mr. Riley said the county coroner planned to disclose the names of the dead. He said the cause of the fire was under investigation.

The fire broke out about 7 p.m. Monday in the Sofa Super Store and warehouse, forcing officials to close off part of a nearby roadway.

Witnesses said the store’s roof collapsed, throwing debris over about two-dozen rescue workers. Onlookers were hit with flying ash.

“It was like a 30-foot tornado of flames,” said Mark Hilton, who was struck in his eye.

Mr. Riley said he believed all of the store’s employees escaped. At least one worker and two firefighters were taken to the hospital.

Daniel Shahid, a salesman at a nearby car dealership, said firefighters came in asking for towels.

“The next thing you know, we were carrying hoses, directing traffic, everybody from the dealership,” he said.

Mr. Shahid said he saw firefighters rescue four people from the building. “They were struggling. They were covered in black soot. They looked scared out of their minds,” Shahid said.

Mr. Riley called the missing firefighters heroes. “This is a profession that we must never take for granted,” the mayor said. “There’s a fire raging and they go toward it.”