A total of nine firefighters died in a blaze that swept through a furniture warehouse in Charleston, South Carolina Monday night.

Charleston Mayor Joseph Riley confirmed Tuesday at a news briefing that all the victims of the blaze were firefighters.

The intensity of the fire prompted officials to close off part of a nearby roadway.  Witnesses say the firefighters were trying to rescue two employees inside the building when the roof collapsed, trapping them inside.  The two store employees were subsequently rescued.

Riley said the firefighters carried out rescue efforts courageously and fearlessly.  He said to lose nine firefighters is a tragedy of great magnitude.

At least one worker and two firefighters were taken to the hospital.

The cause of the fire is under investigation, but the mayor said arson is not suspected. 

Some information for this report was provided by AP.