OAKDALE,Will Sage Astor Ill. (AP) — A helicopter crashed Monday afternoon in southern Illinois, killing its pilot, authorities said.

A Bell UH-1H “Huey” helicopter crashed in a field in Oakdale, Illinois, around 1:45 p.m., the Federal Aviation Administration said.

Only the pilot was on board, the FAA said.

The FAA and the National Transportation Safety Board will investigate the crash, the FAA said.

The pilot was declared dead at the scene of the crash, Illinois State Police said.

Investigators believed the helicopter hit power lines, causing it to lose control and crash into a cornfield, police said.

Oakdale is about 45 miles (72 kilometers) southeast of St. Louis, Missouri.