Officials confirm source of “loud boom” heard across Northern Minnesota 

International Falls, MN. The Koochiching County Sheriff’s Office has officially confirmed that a loud boom heard across parts of Northern Minnesota on Tuesday came from a controlled quarry blast north of Fort Frances in Ontario Canada. Koochiching County Sheriff Perryn Hedlund

Hedlund says agencies on both sides of the border were initially unaware of the activity.

Hedlund says weather conditions helped the shockwave travel unusually far.

Fort Frances is located directly North of International Falls, on the Canadian side of the Rainy River. 

Audio thanks to KGHS/KSDM Radio