DULUTH, Minn. — An expensive piece of logging equipment has to be replaced after it was destroyed by fire, and investigators near Duluth suspect it might not be an accident. 

Fire crews were called to a logging site off Alden Lake Road just north of Duluth around 12:45 p.m. Saturday on reports of equipment on fire. They were able to quickly put the fire down but the machine, a nearly-new Caterpillar 521-B Feller Buncher, was determined a total loss. Replacement value is $500,000. 

The machine is used to pull trees from the ground and stack them. 

The machine was owned and operated by Doug Hustad Logging. At the time of the fire, the operation was idle, and detectives are investigating the incident as a possible arson. 

"We definitely have some people who are unhappy with the Line 3 project," said Sergeant Wade Rasch of the St. Louis County Sheriff's Office, who added that other environmental interests might also have motive to see the logging operation idled. Rasch says the State Fire Marshal has not ruled out an electrical malfunction as a potential cause, but added that scenario is extremely unlikely due to the new condition of the machine.  

Anyone who was in the area before the fire and may have seen something suspicious is urged to call the St. Louis County Sheriff's Office Investigations Division at 218-336-4350.