A St. Paul school bus crashed into a minivan Wednesday morning, causing a four-car crash and the death of one woman, according to the Pioneer Press.

The bus was travelling about 55 miles per hour on Interstate 94 when it crashed into the minivan, which was caught in slower traffic, according to State Patrol Lt. Eric Roeske, reported the Star Tribune.

Nang Nguyen, 75, was killed in the crash. Nguyen was sitting in the rear of the minivan and died at the scene of the crash.

There were five other passengers seriously injured in the crash and taken to local hospitals.

The bus was travelling to the Minnesota Central Bus Co. depot at the time of the crash, and was not carrying any passengers.

The bus driver, Tony Thao, 51, was treated at Regions Hospital, according to the State Patrol.

 "We don't know any of the details yet." Frank Ciccarella, director of safety and training for Minnesota Central Bus

"We are trying to ascertain what happened,"