MANCHESTER, Minn. — Authorities say a 79-year-old man was killed during a fire at his farmhouse in Manchester.

According to Freeborn County Sheriff Kurt Freitag, the blaze broke out Monday afternoon as homeowner Edson Lebeck was working on a water heater in his basement. He tells KTTC-TV ( ) that firefighters spent several hours trying to extinguish the fire and eventually found Lebeck dead inside the home.

The state fire marshal is investigating the blaze. It's still unclear what caused the fire and how much damage it caused.