BIDDEFORD (AP) – Building and insurance inspectors determined Sunday that a downtown building that was destroyed by fire would have to be torn down.

Officials were making plans to demolish the three-story Mahaney Building that was gutted Saturday by the four-alarm fire that apparently began in a trophy shop on the ground floor.

Building owner Ed Caron said the owner of Coastal Awards, Eunice Marquis, told him that she was using a laser engraving machine when it caught fire.

“She thought it was some sort of electrical problem in the machine,” Caron said.

The fire spread quickly through the 15,000-square-foot building on Alfred Street, which also housed law and accounting offices.

Neighboring communities, including Saco, Kennebunk and Old Orchard Beach, helped battle the blaze. One firefighter was treated at Southern Maine Medical Center after suffing minor sprains and bruises from a fall.

Hundreds of onlookers gathered near the fire, which produced a steady plume of thick smoke that could be seen miles away.

Caron’s law office was in the building that he said was built around 1900 by one of the city’s founding families and was historically significant. The building underwent $500,000 worth of renovations in 1986 that included additional structural support and fireproofing, and Caron put on a new roof this summer.