Officials in Bergen County say that it is unlikely investigators will ever figure out the exact cause of a fire that destroyed an iconic paper mill in Elmwood Park.

The Bergen County Prosecutor’s Office says that the fire that destroyed the Marcal Paper mill January 31 was too intense and left too much damage to enable investigators to determine an exact cause. The fire destroyed 31 out of the 36 buildings on the Marcal campus.

No one was hurt in the fire.

Officials say that the fire started in the storage area of one of the buildings on the campus, which contained large roles of paper used to make paper products for the company.

Investigators have ruled the cause of the fire to be accidental.