KITTERY, Maine (AP) State police in Maine are investigating a fatal highway crash that appeared to involve a wrong-way driver.

Police said the crash happened in the early morning hours of Thursday in Kittery when a passenger car and tractor-trailer truck collided on the Maine Turnpike. The crash killed Caleb Ewing, 29, of Caribou, who was the driver of the car, police said.

Police said the driver of the tractor-trailer was uninjured. They said an initial investigation showed Ewing entered the turnpike in Kittery and traveled in the wrong direction, going northbound in the southbound lane.

Police said the driver of the tractor-trailer couldn’t avoid the collision. They said the investigation was still going on Thursday and it was unclear what factors caused the crash.