SIOUX FALLS, S.D. -

An historic building that used to be owned and operated by John Morrell & Co., is likely a total loss.

A fire broke out in the second level early this morning.

It took 8 Sioux Falls Fire Department units 6 hours to put out the fire at the old John Morrell Livestock Exchange Building.

Crews were dispatched a little after midnight to the 800 block of East Rice Street.

Upon arrival, firefighters attacked the inside of the building first, worked their way to the outside, and then stuck around for lingering hot spots.

Fire Capt. Clint Deboer says it was a tough fire to control.

Not only are attic fires hard to access at night, but the thunderstorms passing through the area made it that much more difficult.

"The storm that came through had a lot of lightening and there were definitely threats with that because we're using ladders to access the building and they're steel ladders,” says Capt. Deboer. “We have to stop operations and let the storm pass through."

Deboer says it appeared homeless people were staying inside the now vacant building.

There were no injuries reported, and no surrounding buildings were affected.

Police blocked off one block of E. Rice Street from midnight until noon today to let crews finish cleaning up the area.

The cause of the fire is still under investigation.