The girls were on top of the train when they fell between cars at the 111th Street station in Corona just before 11 p.m.
They had boarded at the Flushing Main St. station, and were running on the top of moving subway as it headed west, jumping between train cars, police say.
When the train came to a stop, the girls lost their balance. One fell under the train and was killed.
The other suffered a head injury, including bleeding on the brain, and is intubated in critical condition at Elmhurst Hospital.
This marks the sixth subway surfing death this year. Just last week, a 13-year-old fell to his death while subway surfing at the Forest Avenue subway station, also in Queens.
Five people were killed subway surfing last year.
Despite the most recent death, less than 12 hours after the accident, witnesses said they saw other young people doing exactly the same thing in exactly the same place -- with no obvious police presence to deter them or to stop them.
Police commanders insist that enforcement has been stepped up. Surveillance teams are using drones along certain elevated lines that are popular with subway surfers.
The NYPD's newly appointed transit chief told MTA board members the department is committed to stopping it.
"We have a drone program that is on that J line, on that 7 line, where predominantly see it," said NYPD Transit Bureau Chief Joseph Gulotta. "We're hitting social media hard. We're putting out videos with parents. We're showing the effects that this has on it."
Some MTA board members are calling for more effective outreach in addition to better enforcement.
"You feel invulnerable at this time in your life that nothing can happen, that every adventure will always end happily and we have to have people who they respect and listen to and are in their world and telling them, 'No, this is not the way.' There are other ways to validate yourself," said MTA board member David Jones.
Mayor Eric Adams said he was heartbroken to hear of the latest death.
"Heartbroken to hear that subway surfing - and the pursuit of social media clout - has stolen another life," Adams said. "We are doing everything we can to raise awareness against this dangerous trend, but we need all New Yorkers - and our social media companies - to do their part, too. No post is worth your future. My prayers are with the families of both girls."
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