A driver is dead after a major car crash involving an 18-wheeler.

The accident happened around 9 p.m. Friday in northwest Houston.  Police said a truck driver was backing into a driveway when he noticed two cars speeding toward him.  He reportedly tried to get the drivers' attention, but he was unsuccessful.

The driver of one of the cars -- a BMW -- didn't stop and slammed into the semi-truck with such force that the car went all the way under the truck and crashed into a fence. 

Police said the car's driver was killed instantly.  His name was not immediately released.

The truck's driver was not harmed.