Firefighters stand on a hillside in Belfast as Penobscot McCrum burns below them. Credit: Abigail Curtis / BDN

BELFAST, Maine — Last week’s devastating fire at the Penobscot McCrum potato processing plant in Belfast may have started on a conveyor belt that runs directly alongside a large fryolator, according to Maine State Fire Marshal Joseph Thomas. 

But because the damage from the fire is so extensive, the cause is undetermined, with Thomas’s office unable to identify whether it was caused by a spontaneous combustion of leftover food at the end of the conveyor, or by a mechanical issue, according to officials from the city of Belfast. 

The fryolator previously had been pinpointed as a potential cause of the fire. But the new theory — developed after investigators spoke with McCrum employees who were in the building when the fire began — could help explain how the fire seemed to move around the structure so fast, Thomas said Wednesday morning. Everyone who was in the building when the fire started made it out unharmed and city officials said the fire has been ruled accidental. 

From the conveyor belt, flames could have spread into the building’s air duct system that exits through the roof, and extended into the empty space between the ceiling and the roof, city officials said. 

“It does make sense as to how the fire spread throughout the building into the void spaces,” Thomas said. “It certainly got into the ventilation system and consequently got out of reach of the fire suppression system.”

According to Bub Fournier, the director of the Belfast code and planning department, the McCrum building appeared to have met fire and life safety codes. 

“I don’t believe there were any open violations from our office,” he said. 

The McCrum building appeared to have met fire and life safety codes, according to Bub Fournier, the director of the Belfast code and planning department. 

The fire marshal said his office is looking into whether information gleaned from the McCrum fire will shed light on whether state fire codes may be insufficient for similar processing plants. 

“How did these things take place that allowed the fire to get around the safety measures that were in the building?” Thomas said. “A situation like this could help us enhance the fire codes. There will be lessons to be learned.” 

State investigators are continuing to look into what happened at Penobscot McCrum and will do so until they file their final report, he said. They are interviewing employees and doing an analysis of the debris left behind. Investigators suspect large quantities of cooking oil used to fry the potatoes played a part in the fire development, he said.  

The interviews and clues found amid the debris will allow investigators to create a visualization of what happened, he said. 

Although employees tried to put the fire out, they could not. 

The fire marshal said he believes that only eight or so employees were working in the building as a cleaning crew when the fire began around 2 a.m. on Thursday, March 24.

It took them more than seven hours to knock down the flames and the remnants of the factory continued to smolder for well over a day. Because of the fire, 138 employees are out of work for the time being. 

“Given the size of this property, the rapid spread of the fire and imminent threat of hazardous materials, we are so fortunate that all the employees were accounted for early and safe,” Belfast Fire Chief Patrick Richards said. 

It was not the first fire at the property. In 2019, the Penobscot McCrum administrative building caught fire and was ultimately razed. No one was injured in that fire, either, and the company ultimately moved its administrative offices to a different site at the corner of routes 1 and 52 in Belfast. 

“It does happen,” Thomas said of multiple fires occurring at the same location. “People need to take fire safety in their buildings seriously. If you don’t think about it every day and do the things you need to do to protect yourself from fire, it can and will happen.” 

But too many do not, he said, and are heedless about the risk of fire. Several recent outdoor fires have been caused by people carelessly throwing burning cigarette butts outside, he said.

“The public is complacent about fire in this state. No question in my mind,” he said. “If people were paying attention to why fire safety is impressed upon so much, a lot of these incidents probably would not have to happen.”  

Correction: A previous version of this article incorrectly stated the cause of the fire.