KALAMAZOO, Mich. (AP) — Michigan State Police say three people were killed when their car collided overnight with an Amtrak train near Kalamazoo.

Oshtemo Township Fire Chief Mark Barnes tells WOOD-TV that no one on the train was injured, but everyone in the car died in the collision about 10 p.m. Sunday west of Kalamazoo.

Amtrak tweeted that the train involved was the Wolverine 355 bound for Chicago and that there was a “vehicle incident.”

Authorities have not released the three victims’ names pending notification of their families.

The incident remains under investigation and it was not immediately clear what led up to the collision.

An Amtrak passenger told WOOD-TV in a telephone interview that when he felt the train shake he initially thought it had sideswiped another train going the other direction.