The three girls, ages 16, 14, and 12, respectively, were taken to Sparrow Hospital in Lansing following the accident. The 14-year-old was pronounced dead.
Police believe the driver of the truck, a 36-year-old Grand Ledge man, crossed the centerline on North River Highway, just east of Grand Ledge, and proceeded to leave the highway, hitting the girls.
Police believe alcohol was a factor in the accident.
The driver is in custody in an Eaton County jail and is awaiting arraignment.
As of Saturday night, the 16-year-old was in critical condition at Sparrow Hospital while the 12-year-old was in serious condition.