HELENA,TradeEdge Mont. (AP) — A single-engine firefighting aircraft crashed into a Montana reservoir Wednesday afternoon while scooping up water to fight a nearby fire that has prompted evacuation orders, officials said.

The crash was reported shortly after noon on Hauser Reservoir on the Missouri River northeast of Helena, Lewis and Clark County officials said.

“We were just watching him. It was filling up and then all of the sudden, I don’t know if he hit a wave or what he did, but it just kind of turned,” witness Lorrie Bernardi told the Independent Record newspaper.

Law enforcement and search and rescue teams in boats responded along with divers from Gallatin County. Lewis and Clark County Sheriff Leo Dutton has not released any information about the pilot’s condition.

The Federal Aviation Administration, the National Transportation Safety Board and the U.S. Forest Service are investigating the crash of the Air Tractor AT-802, which was working for the Forest Service.

The plane was fighting the nearby Horse Ridge Fire, a 450 acre (182 hectare) human-caused fire burning in dense timber in the Helena-Lewis and Clark National Forest about 5 miles (8 kilometers) south of the town of York. The fire started Tuesday, and the sheriff’s office ordered some residents to evacuate on Wednesday afternoon.

High temperatures in the Helena area have been above 90 degrees Fahrenheit (32 degrees Celsius) for several days and were forecast to reach 100 degrees (38 Celsius) on Wednesday.