WEST ENFIELD (AP) – Investigators were seeking the cause of last weekend’s fast-moving fire that demolished a lumber mill, jeopardizing as many as 50 jobs.

The owners of Cold Stream Lumber Co. said they plan to rebuild the mill that cuts about 12 million feet of white pine a year for the wholesale market.

The mill building, measuring 100 feet by at least 50 feet, was completely ablaze when firefighters arrived early Saturday, minutes after the first alarm sounded, officials said.

“The building was destroyed on arrival,” Howland Fire Chief Philip Dawson said. “It was … starting to fall in on itself. She was done.”

Dawson radioed for help from fire departments in Lincoln, Passadumkeag and Seboeis, but crews had to wait 20 to 30 minutes for a Bangor Hydro-Electric Co. crew to come to the site and shut off electricity.

Several lines could be seen arcing in the flames, smoke and darkness, and Dawson said it was too hazardous to douse the mill until the power lines were shut off. But the delay was inconsequential, firefighters said.

“There was no stopping it. The delay for Hydro wasn’t going to change anything,” said Lincoln firefighter Rick Smart. “The fire was still going to be contained to that building no matter what we did, but there was no way we were going to save that building.”

There were no reports of injury in the fire, Dawson said.

The wood-planing mill and several drying kilns that were untouched by the flames were back in operation Monday.

The mill’s owners, Bruce Hamilton of Brewer and Fred Schult of Hampden, have run the company for about 16 years, and both said they hope to rebuild on the site off Route 155.

Cold Stream has a work force of about 50, including 43 full-time hourly employees and support and managerial staff, said Hollis Moon, a company foreman.