Sanilac Central Dispatch received a call regarding an accident involving two vehicles on May 16.
Officials said two vehicles collided at the intersection of S. Sandusky and Miller Roads causing a personal injury accident.
According to Sgt. Matt Armstrong, the investigation determined a 2011 Chevrolet Impala - driven by an 87-year-old from Marlette - was traveling westbound on E. Miller Road, east of S. Sandusky Road when she failed to stop.
The Impala was then struck by a 2008 Chevrolet Silverado traveling southbound. Officials said that car was occupied by a 66-year-old man and a 63-year-old woman, both from Marlette.
According to officials, the 87-year-old was not wearing a seatbelt. The passengers in the Silverado were wearing seatbelts. Officials said that airbags were deployed in both vehicles.
All three people were taken to McKenzie Hospital. The 87-year-old was later transported to Saginaw Covenant for further treatment.
Officials do not believe alcohol or drugs were a factor in this accident.
Their names are being withheld pending the investigation.