TURNER — Police on Wednesday were trying to determine what caused a 73-year-old Gray man to veer into oncoming traffic on Route 4 on Tuesday, costing him his life.

Androscoggin County Sheriff’s Office investigators said Leon Beaulieu had been driving south at about 6:30 p.m. Tuesday when his 1994 Dodge Ram van crossed the centerline and collided with a 2003 Chevrolet pickup truck, driven by 35-year-old Benjamin Ouellette of Greene.

Beaulieu was dead when emergency crews arrived on the scene. Ouellette, driver of the Chevrolet pickup truck, suffered serious injuries.

Both victims had to be extricated from their vehicles, police said.

Ouellette was taken to Central Maine Medical Center in Lewiston, where he was listed in good condition Wednesday.

What caused Beaulieu to drive across the centerline remained a mystery. A Lewiston police crash reconstructionist is assisting the Sheriff’s Office with the investigation.

The collision occurred between Route 117 and Mancine Road.