A medical helicopter carrying three people crashed in northern Wisconsin Thursday (April 26, 2018) killing all three flight crew members on board. The crash occurred late Thursday night about 150 miles northwest of Green Bay in an unlighted rural area after having dropped off a patient in Madison, Wisconsin.

The Ascension Health Spirit helicopter crashed in a heavily wooded area near Hazelhurst. Wisconsin. "Because of the lack of lighting in rural areas, visual orientation is critical and pilots need to know exactly where they are so that wrong decisions are not made," Durkin said.

Investigators from the National Transportation Safety Board (NTSB) are on the scene sifting through the wreckage in order to determine the probable cause of the helicopter crash. In the past decade, there have been 83 medevac crashes involving 100 deaths, according to ABC News.

"Pilots in medical helicopters are fully aware of the life-and-death circumstances of the patients they are to transport, but they cannot take that into consideration when deciding whether it is safe to fly, particularly at night and in rural areas" Durkin said. "Medevac transportation involves the initial decision to determine if the flight is medically necessary, and then the decision if meteorological conditions allow for it. As the facts develop in the Wisconsin crash, experts will determine the cause of this terrible tragedy and what went wrong."