A four-car accident on Hwy. 377 Tuesday claimed the life of 12-year-old Flower Mound boy.

The accident occurred just after 4:00 p.m. at the intersection of Hwy. 377 and Stonecrest Road.

Flower Mound Police said that a Ford F-150 pick-up stopped on Hwy. 377 northbound to turn left onto Stonecrest Road was rear-ended by a Honda, forcing the truck into the path of a silver Mazda Millennia traveling south on US 377. 

The driver of the Mazda swerved and lost control of his vehicle, striking a Cadillac driving north on Hwy. 377.  12-year-old Robert Key of Flower Mound, a passenger in the Mazda, was pronounced dead at the scene. Key was a sixth-grader at Liberty Christian School.

The driver of the Mazda was transported by Careflite Air Ambulance to Harris Methodist Hospital in Fort Worth in unknown condition.  An additional passenger of the Mazda was transported to Baylor Hospital in Grapevine in stable condition.  No other drivers or passengers were seriously injured, police said.

The cause of the collision is still under investigation.