UPDATE: The North Dakota Highway Patrol says a 76-year-old female from Harvey and a 75-year-old male from Rugby were the two fatalities. The seriously injured passenger is an 80-year-old female from Rugby. The driver of the tractor-trailer has been identified as 54-year-old Terry Goeser of Casselton. Goeser was not injured.

ORIGINAL STORY: Two people are dead following a two-vehicle crash in Cass County this morning.

According to Cass County Sheriff Jesse Jahner, the crash happened at just before 10 a.m. today at the intersection of Cass County 20 and Cass County 17. In addition to the Sheriff's Office, the North Dakota Highway Patrol, FM Ambulance, Harwood Fire and Rescue and Sanford LifeFlight all responded to the scene, involving a tractor-trailer and a passenger van.

Jahner says the driver of the tractor-trailer was not injured.

Three people were in the passenger van, he says. One of the occupants were lifeflighted to Sanford in Fargo with serious injuries, while the other two died in the crash.

The North Dakota Highway Patrol is investigating the crash.

"We do not know the cause of the crash at this time," Jahner said. He says he doesn't believe the road surface had anything to do with the crash. Snow had fallen earlier in the day.

The portion of the road is still closed as of 12 p.m. Friday because of the investigation.