A 53-year-old Tacoma man died in his vehicle on the shoulder of Highway 16 this morning of an “unknown medical condition,” the State Patrol reported.

The man was driving eastbound near the 19th Street interchange about 5:30 a.m. when he pulled his Chevrolet van onto the left shoulder, troopers said.

Troopers found him dead inside the van when they arrived on the scene.

The incident is under investigation.