Nearly 70 firefighters from Salt Lake City and the Unified Fire Authority battled the flames for more than two hours. Firefighters on ladder trucks doused the fire from three sides, while others worked inside.

When an alarm sounded, firefighters on the inside were forced out of the club and began to focus on saving an adjacent building.

"We believe the (DV8) building is in imminent danger of collapse," Andrus said around 9:30 p.m.

The fire was the largest in Salt Lake City since a March 2003 fire destroyed a strip mall near 500 E. South Temple, he said.

Just before 10 p.m., crews started to get a handle on the fire.

Most firefighters were taken off the building around 11 p.m., but Salt Lake firefighters planned to stay on the scene and tend to hotspots throughout the night and for most of today, he said. "This building will likely burn for a couple of days," Andrus said.

No injuries were reported Wednesday night. The DV8 building had reportedly been vacant for some time.

"As far as we know, there was no one inside," Andrus said. "But we couldn't get a good search on it."

Crews were able to save an adjacent building to the south of the old club. Both buildings are owned by the same person, officials said.

"He was very relieved the fire didn't spread," Andrus said.

The cause of the fire was unknown Wednesday night, and it could be a few days before investigators release any findings, Andrus said. He estimated damage to be building would be more than $500,000.

Hundreds of people gathered downtown to watch the building burn.

Patrons of a nearby restaurant said they could smell smoke coming through the vents and decided to leave that building at about 8:45 p.m.

A man walking by said he "saw a light" in the building around 8:40 p.m. "There was another flicker on the first floor," said Rob Holmes, a Los Angeles man who called 911. "Then you could start to see smoke coming from all the seams."

Club DV8 opened in 1989 as a downtown dance club. The venue, known as X-Scape for a time, hosted a number of live concerts before closing its doors.