A fire that raged for days in February in a towering scrap pile at the Northern Metal Recycling yard in Becker, Minn., was set by accident, according to a report released Wednesday by the State Fire Marshal's Office.

Law enforcement agencies responding to the fire saw no indication in the freshly fallen snow that anyone had tried to climb the 60-foot-tall metal pile. Their dashboard and body cameras showed that the fire was burning far into the metal debris, with no contact to the outer edges, the report says.

"Due to this evidence, I did not find any intentional reasons for the fire starting," wrote lead investigator Casey Stotts.

According to the report, the fire started in the early morning of Feb. 18 some 20 to 30 feet into a pile of crushed vehicles, appliances and miscellaneous scrap metal at 12432 SE. Energy Drive. The business is in the process of moving its operation from north Minneapolis to Becker and was due to open within five days of the fire.

Although batteries are supposedly removed from the vehicles before they're received at the yard, some occasionally slip through, workers told fire investigators.

Stotts said he could not rule out that a discarded battery or some "water-reactive metal" may have sparked the fire in combustible materials in or around the piled vehicles.

He concluded the fire was caused by accident, though he reserved the right to amend or modify his opinion if he gets additional information.

The company was cited in February for fire-code violations at its north Minneapolis location related to storing vehicles in stacks more than 20 feet high. Northern Metal ceased shredding operations there when the Minnesota Pollution Control Agency ordered it to shut down last fall after finding high levels of air pollutants in the neighborhood. It now only stores junked vehicles at the site.

The fire at the company's new site in Sherburne County sent flames leaping 50 feet in the air and created a plume of noxious black smoke that spread for 20 miles. It burned for several days as firefighters from numerous departments hauled in water and crews used heavy equipment to pull apart the stacked scrap heap.