TULSA, Oklahoma - Fire destroyed a Tulsa office building housing the Petroleum Equipment Institute late Tuesday.

The Tulsa Fire Department got the call at about 9:15 p.m.

Firefighters arrived to find the 5,000-square-foot building on fire in the 6500 block of East 69th Street. Firefighters began an interior attack but were forced back out when the roof started to collapse.

Firefighters had to battle ice forming on their gear as well as the fire.

"It affects 'em, it puts weight on 'em.  And plus the hazard, you know, just the slip hazard is our main problem," said Tulsa Fire Captain Jerry Sivadon.

The building was destroyed. The cause of the fire remains under investigation. 

Fire officials said no one was in the building at the time.

According to their web site, the Petroleum Equipment Institute is a not-for-profit trade organization dealing with petroleum marketing operations.