Two teenagers were found dead in what New York City police are investigating as a possible subway surfing incident, sources tell CBS News New York. 

Transit workers at the Marcy Avenue station in Williamsburg, Brooklyn, found the girls' bodies, NYC Transit President Demetrius Crichlow said. Police sources tell CBS News New York they were found on top of a J train with head trauma.

The teens were pronounced dead at the scene at around 3 a.m. Saturday, shortly after officers arrived, police said.

Their names and ages were not immediately released by officials.

NYC Transit President Demetrius Crichlow released the statement: "It's heartbreaking that two young girls are gone because they somehow thought riding outside a subway train was an acceptable game. Parents, teachers, and friends need to be clear with loved ones: getting on top of a subway car isn't 'surfing' – it's suicide. I'm thinking of both the grieving families, and transit workers who discovered these children, all of whom have been horribly shaken by this tragedy."

"I am heartbroken that two New Yorkers lost their lives last night while subway surfing in Brooklyn. Subway surfing is serious and the consequences are deadly. We will continue working with the [MTA] and [NYPD] to ensure that young New Yorkers ride inside and stay alive," Gov. Kathy Hochul wrote in a post on X.

The station at the corner of Marcy Avenue and Broadway was shut down, and J and M trains were bypassing the stop while first responders were on the scene.

Service has since resumed, according to the Metropolitan Transportation Authority.

Some commuters at the Marcy Avenue station say subway surfing is all too common there.

"This is something that constantly happens at this station alone. The J line is high on subway surfing. It's sad, but it doesn't surprise me," commuter Bernadette Hardnett said.

"It's not worth it, and I can't stress that enough"

Emely Oliver said her 15-year-old brother, Carlos Oliver, died from subway surfing three months ago.

"To see that his happened to someone else's family ... it's just such a shock," Oliver said.

She fought back tears as she reflected on her family's loss.

"He didn't get to be a man yet, and now he never will be," she said. "My little sister lost her big brother. I lost my little brother. My mom lost her only son."

According to the NYPD, three people have died due to subway surfing so far this year, and 128 people have been arrested after being caught subway surfing.

"It's not worth it, and I can't stress that enough," Oliver said.  

Subway surfing a deadly danger in NYC

Sixteen people were killed and 21 were injured from subway surfing in the city over the past three years, according to NYPD data provided in September. 

In June, a teen was critically injured riding on top of a 5 train in the Bronx. The boy suffered head and wrist injuries as the subway pulled into the Baychester Avenue station. A police source at the time said the boy fell onto the track bed and made contact with the train. 

Last October, a 13-year-old girl was fatally struck by a 7 train in Queens after she fell onto the tracks while subway surfing and was struck, according to NYPD. 

Days after the girl's death, the NYPD and Mayor Eric Adams touted a drone program to spot people taking part in the dangerous and illegal activity and get officers along the route as soon as possible. At the time, police said 900 drone flights saved the lives of 114 people, from 9-33 years old. 

The MTA also rolled out the "Ride Inside, Stay Alive" campaign in September 2023, which is aimed at discouraging subway surfing, especially among younger New Yorkers who may be influenced by social media.

That campaign was revamped this summer, featuring BMX athlete Nigel Sylvester as the campaign ambassador.