Investigators say fatal Maine lumber mill fire was accidental and started in silo

PORTLAND, Maine (AP) — The fire and subsequent explosion at a Maine lumber mill that killed a firefighter and injured a dozen other people was accidental and originated at the base of a silo, authorities said Tuesday.

The May 15 fire and explosion at Robbins Lumber in Searsmont killed Andrew Cross, 27, of the Morrill Volunteer Fire Department. The injured people include members of the family that runs the lumber mill and other emergency responders. The fire sent plumes of black smoke into the sky and required hundreds of firefighters from dozens of departments to suppress it.

Rapid ignition of particulate material resulted in an explosion in the silo that caused it to lift from its concrete base and release large amounts of sawdust and other materials, the Maine State Fire Marshal’s Office said in a statement Tuesday. The silo then toppled and the surrounding area became engulfed in fire, the office said.

Investigators will return to the facility in the coming months to conduct a more detailed examination, the fire marshal’s office said.

“Investigators also determined the facility’s fire suppression system, which was located near the top of the silo, did not activate because temperatures at that elevation did not reach the activation threshold after the fire originated at the base of the silo,” the office’s statement said.

Lumber mills are major sources of combustible dust. High winds during the investigation delayed the investigation’s findings, Maj. Aaron Turcotte, a spokesperson for the Maine Department of Public Safety, said last week.

“High winds throughout the day created difficult working conditions on scene, resulting in flying debris and periodic interruptions to investigative operations. Drone operations and aerial photography were particularly challenging due to the wind, causing delays in some scene documentation,” Turcotte said in a statement.

The explosion in Searsmont, about 95 miles (150 kilometers) northeast of Portland, triggered a massive response from emergency responders to a rural part of the state. Investigators from the state fire marshal and the federal Bureau of Alcohol, Tobacco, Firearms and Explosives took up the investigation in the aftermath of the explosion and fire, which took hours to contain.

Gov. Janet Mills later ordered flags in the state lowered to half-staff last week in honor of Cross.

“My heart goes out to the family, friends and colleagues of Andrew Cross,” Mills said. “He died a hero.”

Robbins Lumber’s website describes the company as a “high-tech lumber manufacturer” that has been in existence since 1881 and family-owned for five generations. Christian Halsted, a family spokesperson, said after the fire that it was a “hugely devastating day for the family” and that the family was cooperating with the investigation.

Lumber and wood products are a critical and historic industry in Maine. The Maine Forest Products Council said it contributed more than $8 billion to the state’s economy in 2024 and provides about 29,000 jobs.