HAZELTON, Idaho - A truck driver has died at the scene of a rollover crash on Interstate 84 near Hazelton Sunday morning.

The driver, 78-year-old Joe Townley Jr. of Anderson, Calif., suffered a medical emergency before losing control of the semi, which crossed the median and rolled over in the oncoming lanes of the freeway, Idaho State Police said.

The truck came to rest on the eastbound shoulder of the interstate, blocking lanes on a frontage road.

A passenger, 57-year-old Mark Zahler of Brooklyn, New York, was also in the truck at the time of the crash. He was transported to St. Luke's in Twin Falls. His condition is unknown.

Police said both men were wearing seatbelts.

It is unclear if the driver died from injuries related to the crash or from the medical emergency.

The frontage road south of I-84 was blocked for an extended time while crews worked to clear the scene.

ISP is continuing to investigate the crash.