The cause of the fire that killed 7,500 and 8,000 pigs and destroyed a pig barn last month southeast of Hartland is still under investigation by the State Fire Marshal’s Office.

Arson is not suspected in the fire, said Freeborn County Sheriff’s Office Sgt. Tim Bennett.

The fire was reported to the Sheriff’s Office on the afternoon of Jan. 7. Fire crews were dispatched to 71082 300th St. According to the Sheriff’s Office, the fire started in a wall on the south side of the building near an office area. The reporting party reportedly tried to put the fire out but was unable to do so.

The fire spread up the wall and into the ceiling throughout the building.