DALLAS (CBSDFW.COM) – A crash that happened just before midnight shutdown part of the Dallas North Tollway in Plano.

A spokesman with the Texas Department of Public Safety (DPS) says what ultimately was a 4-vehicle crash is believed to have started with a Mustang traveling north on the Tollway. Investigators believe the driver – for some unknown reason – ran into a BMW traveling in the same direction.

READ MORE: World Series Notebook: Home Team Finally Wins At Home 

The collision sent the Mustang spinning and it smashed into two other vehicles.

(credit: CBSDFW.COM)

READ MORE: No. 16 Baylor At Home Could Knock Texas Out Of Big 12 Race

The driver and a passenger in the BMW were taken to Texas Health Presbyterian Hospital in Plano with serious injuries. There were no serious injuries in the other vehicles involved in the crash.

The driver of the Mustang was arrested on suspicion of Driving While Intoxicated.

MORE NEWS: Oil Chiefs Set To Testify At Landmark Congressional Hearing

Traffic is being forced off the Tollway at Parker Road while the investigation into the accident continues.