INTERNATIONAL FALLS, Minn. (From news reports) -- A fire inside Packaging Corporation of America's Boise paper mill in International Falls kept local firefighters at the scene for about five hours on Sunday, May 23.

Falls Fire Chief Adam Mannausau said the fire, reported at 5:09 p.m. appears to have been caused when a Minnesota Power outage affecting about 4,500 customers caused a hard stop to the No. 1 paper machine at the mill.

"It does appear that the power outage was a contributing factor to the cause of the fire," he said. "Preliminarily, it sounds like the hard stop due to the lack power is different than normal shutdown or emergency shutdown procedures that are usually associated with that machine."

No injuries were reported in the emergency, Mannausau said, adding there appeared to be some damage to the paper machine.

Lori Lyman, a PCA spokesperson, confirmed "a paper fire occurred on the International Falls paper machine winder caused by the abrupt power outage experienced throughout the community."

She said said no employees were injured; all were accounted for when the company promptly engaged its standard emergency response procedure.

About 4,500 customers in the International Falls area were without power for about three hours, from about 4:45 to just before 7:30 p.m.

Amy Rutledge, Minnesota Power corporate communications manager, said Monday morning crews continue to investigate the cause of the outage.

"We do know that a piece of equipment on a transmission line that feeds International Falls failed and we are making repairs," she said.

Rutledge said within an hour of the outage, Minnesota Power had a helicopter in the area to begin the restoration process and crews worked as safely and quickly as possible to restore power to the area.

The Littlefork and Kabetogama fire department were each called to assist at the scene Sunday, Mannausau said.

"We felt this was a large fire and we were going to need additional resources," he said. "Both departments provided equipment and manpower to assist with the call. It was very helpful to have the additional manpower to allow firefighters to rotate through and take some breaks."

At larger incidents, he said a firefighter rehab station is set up, which allows firefighters to take a break, cool off, and get some water.

"When this is happening the ambulance service takes their vitals and does very quick evaluation of them," he said. "We chart those findings and determine if it is safe for that person to continue working on the front lines or if we have to put them in more of a support role until they stabilize. With more people, we can lighten the load on individual firefighters and spread out the work more evenly creating safer working conditions for them."

International Falls Police Capt. Mike Kostiuk said police provided support and assistance with the fire response until the IFFD was able to gain control of the situation.

Officers also conducted traffic control to ensure the continued response had ease of access to the scene.

Kostiuk said no residents were evacuated, after considering the scene safety details and speaking with the fire department officials.