Honolulu firefighters early Saturday morning extinguished a fire in downtown Honolulu that caused an estimated $20,000 in damage to a commercial building and its contents.

The Honolulu Fire Department received a 911 call at 2:53 a.m. Saturday about a rubbish fire at 1141 Bishop St., according to a news release from HFD. The department responded with a unit six minutes later and the fire captain first on scene observed smoke emanating from a two-story commercial building and requested more help.

HFD dispatched an additional five units staffed with 19 personnel. Firefighters attacked the blaze from the basement area then searched the inside to discover no occupants.

The fire was contained to an area measuring 20 feet by 10 feet in the crawlspace above the basement. Firefighters brought the blaze under control and extinguished it at 3:54 a.m.

The cause of the fire is under investigation.