The name of the victim was not immediately released. Autopsy results are pending.
Senties told The Associated Press that the boy and a friend Monday night were riding in the back seat of a vehicle, being driven by the friend's mother, in northwest Houston.
Senties says the victim wrapped a seat belt around his neck, pretending he was being strangled, when he started "choking for real, apparently he got tangled up in the seat belt."
Police say the woman managed to free the teen, who was transported to a Houston hospital and pronounced dead.
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