CHARLESTON, S.C. &

Fire swept through a furniture warehouse, collapsing its roof and claiming the lives of nine firefighters in a disaster the mayor described today 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."

Two employees in the building were rescued from the blaze, which broke out at about 7 p.m. Monday in the Sofa Super Store and warehouse, Riley said. One was rescued quickly, and firefighters punched a hole through a wall of the warehouse to reach the other, he said.

Firefighters, police officers and other rescue workers saluted as the firefighters' bodies were carried from the warehouse during the night.

"To lose nine is just a tragedy of immense proportions," Riley said. "To lose nine is just unbelievable."

The department has 237 firefighters in 19 companies located throughout the city of about 106,000.

The cause of the fire was under investigation, but Riley said arson was not suspected. He said the blaze apparently started in a storage area. He was unsure whether there were sprinklers in the building.

Riley said the county coroner would announce the names of the dead.

Witnesses said the collapse of the roof threw 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.

Eric Glover told CNN that he and a number of other firefighters were at a golf tournament to benefit the family of a firefighter who had recently died when they heard the call come over their department radios. the time he arrived, he said, the roof had already collapsed.

"It all happened pretty fast. They didn't really have a chance," Glover said.

"You're always close to the guys because you spend a third of your life with these guys. Every third day you spend 24 hours there, so you get real close," he said.

Firefighters went to a nearby car dealership asking for towels, said salesman Daniel Shahid.

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

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.

He later told CNN the roof collapsed too quickly for anyone to escape.

"It came from nowhere," he said. "It was a standing structure and five seconds later it was on the ground."

Riley called the 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."

This morning, flowers were left on the sidewalk in front of the wreckage of the one-story furniture store and its adjacent, slightly taller warehouse, both of which continued to smolder.

Gov. Mark Sanford ordered state flags lowered to half staff today.

"These are truly some of South Carolina's bravest, who in this case made the ultimate sacrifice in the line of duty," Sanford said.

The buildings are located on what residents here refer to as the "auto mile," a commercial strip of car dealers, body shops and stereo installers.