Firefighters were trying to find the cause of a large warehouse fire that gutted a business at Campbell Industrial Park on Tuesday and burned dangerously close to several fuel tanker trucks.

The fire at 91-080 Hanua St. was reported at 11:16 a.m. It burned a large pile of tires and sent flames about 50 feet above the warehouse. The smoke could be seen from as far as Waipahu, Honolulu fire Capt. Terry Seelig said.

Firefighters who arrived first found the warehouse collapsing over an auto recycling and salvage company called Tows R Us. About 45 firefighters used water and foam to bring the two-alarm blaze under control in about 20 minutes.

While fighting the fire, firefighters noticed that the heat was melting the lights on three 8,000-gallon tanker trucks filled with flammable vapors. Firefighters sprayed water on the tankers, which belong to Ke’alohalani Fuel Transport and were parked next to Tows R Us. The tankers are used to haul unwanted fuel and had not yet been emptied of the gas vapors.

"There could have been a very catastrophic explosion" if the tankers had overheated, Seelig said.

About 20 percent of the 20,800-square-foot warehouse was damaged, but aside from Tows R Us, where the fire apparently started, five other businesses in the warehouse had little or no damage.

Seelig said damage to the structure and contents was estimated at $800,000.