PENDLETON — A fire broke out late Tuesday night, May 13, behind Walmart in Pendleton, burning through stacks of pallets and cardboard boxes. The police department has opened an investigation into who set the blaze.

Pendleton Fire Chief Tony Pierotti said firefighters responded to the call at 11:30 p.m. on May 13, initially dispatched as a “natural cover fire,” typically meaning a grass or wildland fire. The department sent a couple of brush trucks, but when crews arrived, they found pallets and recycled materials burning behind Walmart.

“Walmart stored the materials in an area mostly away from buildings but the flames were big,” Pierotti said. “The storage units to the north caught some grass fire, but we put those out and there was no damage at all. The fire was contained to recycled materials and pallets.”

The fire, which occurred between Walmart and A2Z Storage, did not reach either structure. It took two hours for crews to fully extinguish the blaze using water hoses and foam, Pierotti said. There also were no reports of injuries.

Pendleton Police Chief Chuck Byram said the cause of the fire is under active investigation and an officer is working on the case.

“ We will use all investigative tools at our disposal in order to find the person or persons that could potentially be responsible for lighting this fire,” Byram said.”The fire department and my personnel responded, and it appears it was intentionally set. We’re going to follow the leads we have to try to find the person responsible.”

The morning of May 14 behind the Walmart, a stack of pallets stood scorched from the flames, and cardboard boxes were scattered on the ground, blackened. A portion of the grass also was scorched, and the smell of smoke lingered in the air.

Pierotti said a fire of that scale puts a significant strain on the city’s resources.

“A fire like that really dumps the city. It takes all hands on deck,” he said. “While we’re fighting those fires, we do our best to keep things in service, but it essentially takes all seven people we have on shift to get it under control.”

Byram encouraged community members to report any suspicious activity. He said anyone who may have seen something unusual should call police and officers will follow up to confirm and investigate.