A crash involving a single tractor trailer left one dead and one injured over the holiday weekend.

It happened on westbound Interstate 84 in Hazelton, Idaho on Sunday.

According to KMVT 11 News, the semi driver experienced a medical emergency while driving on I-84, causing him to lose control of the vehicle and drift across the median into the eastbound lanes. The truck eventually rolled onto the freeway shoulder and came to a stop, blocking 1 lane traveling eastbound and a frontage road.

The driver of the truck died Sunday. It has not been made clear whether he died due to crash related injuries or complications caused by the medical emergency. The passenger made it out of the wrecked vehicle, but neither the condition of the passenger nor the names of the victims have been released. Both parties were wearing seatbelts at the time of the crash.

The truck was carrying several barrels of oil, which spilled into a median ditch during the time of the accident. The highway was blocked for an extended period of time for clean-up.

Idaho state police are still investigating the details of the incident.

Update (3:11 p.m.): The driver of the truck has been identified as 78-year-old Joe Townley Jr., of Anderson, California. He passenger was identified as 57-year-old Mark Zahler, of Brooklyn, New York.