A 15-year-old boy was killed while subway surfing on a train crossing the Williamsburg Bridge in New York City, police said.
The incident happened Monday just after 7 p.m., FOX 5 New York reports.
The teen was standing on top of a northbound J train when he struck his head on a structure and fell below the train.
His name has not been released, and the investigation is ongoing.
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NYC Transit President Richard Davey warned of the dangers of subway surfing in a statement obtained by the New York Post.
"We cannot stress enough how dangerous it is to ride on the outside of trains," Davey said. "Our hearts go out to loved ones at yet another tragic time. We implore other families to speak with their children on the real dangers of what can seem like a thrill but is too often deadly."
Incidents of the dangerous behavior skyrocketed due in part to social media, officials said last summer.
In December, another 15-year-old lost his life while subway surfing on the Lower East Side. In that incident police said he was riding on top of a Manhattan-bound J train when he fell off and hit the third rail of the subway near the Essex and Delancey Street Station, according to FOX 5.
A boy lost an arm while attempting to subway surf on a train at the Roosevelt Avenue/74th Street Station in Jackson Heights in August.