Hawaii County fire prevention bureau personnel and police are investigating a warehouse fire in Keaau reported at 5:18 a.m. today.

Twenty-two firefighters, five engines, a tanker, two medical units and four other units responded to the fire.

A two-story corrugated warehouse building, used as a retail showroom for the sale of water catchment tanks, pumps and acceessories, was engulfed in flames when the first unit of firefighters arrived at 5:26 a.m.

The 60-by-150-foot warehouse, on Kipimauna Street at Melekahiwa Place in Shipman Industrial Park, was also used as an office, storage and manufacturing space.

The fire department said there was heavy damage to the metal beams and supports to the structure, the fire department said in a news release.

The storage areas and office on the upper floor were heavily damaged by the fire because materials were stacked in the storage areas.