The Minnesota Department of Natural Resources says a pilot crashed a fire suppression aircraft Tuesday into a Cass County lake. Eyewitnesses helped rescue the pilot, who survived the crash.

DNR spokesperson Gail Nosek said the agency contracted with the fire suppression aircraft and the pilot was on a proficiency flight when he crashed around 2 p.m. in Inguadona Lake near Longville.

"Pilots must conduct proficiency flights, sometimes called mission currency flights, to meet minimum flight hours each month," Nosek said.

Cass County Sheriff Bryan Welk said in a statement that eyewitnesses helped rescue the pilot, a 56-year-old man from Texas. He was the only occupant and was treated on scene for minor injuries.

Welk's office received reports of the airplane crashing into the southern end of Inguadona Lake. He said there were ongoing efforts to retrieve components of the aircraft in the lake.

The DNR says the crash remains under investigation.