HOUSTON -- A horrified mother was forced to stop her car on Highway 290 at Hollister in northwest Houston on Monday night. 

Her 13-year-old son somehow got his neck tangled in the seatbelt and he was choking.

According to police, the woman was traveling southbound with her two children when one of them shouted that the other was choking. The woman pulled over and tried to get the seatbelt off, but it was locked.

Apparently the boy was strapped in with his seatbelt, but was playing with a second seatbelt. He had wrapped it around himself and wasn't able to release it.

A police officer stopped to help her, and ended up using his pocket knife to cut the seatbelt off the boy.

The teen was rushed to the hospital in critical condition, but he didn't make it.

He was pronounced dead on arrival.

The incident is under investigation.