Trooper Erin Hehl was killed when the helicopter she was in crashed during a training exercise. Sergeant Hehl was flying with a contractor pilot at suburban Frankfort Airport in Illinois State Police helicopter AirOne. They were practicing touch-and-go landings when one of the skids of the A-Star Eurocopter got stuck in mud, causing the helicopter to flip over. The civilian pilot was killed as well. Sergeant Hehl had 70 hours of flight experience, but it is unknown who was at the controls at the time of the crash.

Trooper Hehl is an 11 year veteran of the Illinois State Police. She enrolled in the Illinois State Police Academy in 1986. She began her career in District 3 (now District Chicago), and joined the State Police Marine Patrol in 1987. During her tenure with the ISP Marine Unit, Trooper Hehl became a certified diver. She was reassigned to road duties in 1991, and joined the department helicopter project in 1995. This made her the first female trooper to serve on sea, land an air. Trooper Hehl received a private pilot certificate with a helicopter rating in September, 1997.

Trooper Hehl is survived by her husband, son and a stepson. After her death, Trooper Hehl was promoted to Sergeant.