Two people were killed in a car, semi truck accident on Pere Marquette Highway around noon on Thursday in Mason County.
According to the Mason County Sheriff's Office, a 19-year-old woman, Casey Jean O'Brien of Branch, was driving a 2004 Chevy Cavalier when she tried to make U-turn just south of the US-31 onramp. She then drove into the path of an oncoming semi-truck and trailer, causing the collision.
O'Brien was pronounced dead at the scene.
The 18-year-old passenger, Nicholas Allen Smith from Baldwin, was taken to Spectrum Health Ludington Hospital where he later passed away.
The Mason County Sheriff's Office says the other passenger was Smith's 10-year-old sister, Mackenzie Smith, who riding in the backseat. Mackenzie was flown to DeVos Children's Hospital in Grand Rapids for serious injuries.
The driver of the semi truck, 28-year-old Brett Couturier from Ludington, was not injured.
During the investigation, officers found O'Brien's cell phone opened to GPS. Investigators interviewed people close to the teens and concluded that the three were driving to Michigan Adventures.
From evidence gathered at the scene, the Sheriff's department believes that O'Brien missed the southbound US-31 on-ramp and tried to turn around to go back to the ramp.