It happened around 6:30pm local time outside a gas station 11200 block of Fondren. Police said a group of five teens inside a Jeep were playing with a gun when it accidentally went off, striking one of them.
The teen, believed to be between 16 and 18 years old, was transported to the hospital but was pronounced dead upon arrival.
Witnesses say they're all students at Yates High School, KTRK reported.
Detectives are trying to determine how the teens got the gun, how it went off and why they were playing with it. They said so far everyone inside the Jeep stayed on the scene and is cooperating in the investigation.