A 14-year-old boy is dead and another is fighting for his life after police say they were subway surfing.

The two got on a Manhattan-bound L train at the Broadway Junction train station around 2 p.m. Thursday and started heading towards the Bushwick Ave.-Aberdeen St. stop while standing on the top of the train, the NYPD said. 

“As the train was entering the tunnel, we believe they made contact, knocking them off the train and causing the injuries and death,” NYPD Chief of Transit Michael Kemper said at a news conference. 

Officials pronounced one of the boys dead at the scene. The other was taken to Cohen Children’s Hospital in serious condition.

“We’re losing far too many people to this type of dangerous incident,” Mayor Eric Adams said at the news conference.

According to the MTA, there have been 52 subway surfing incidents this year, three of which were fatal. 

“The overwhelming majority of these subway surfers are juveniles," Kemper said. "They are young, 12 years old and 13 years old."

Adams says last year there was a 366% increase in people riding on the outside of trains, adding that social media has a lot to do with it.

“If you go online right now and put ‘NYC subway surfing,’ our young people are watching 39 million views,” he said. The mayor implored social media companies to take the videos down in order to prevent another life lost.

“The consequences of social media and other online content are tragic and real," the mayor said. "Those who host these platforms and benefit financially and make [a] profit off a public safety endeavor must be held responsible."

In a statement, social media giant TikTok offered its sympathies, while attempting to distance itself from the tragedy. 

"Our deepest sympathies go out to family and friends of the young person involved in this incident. This dangerous activity predates our platform, and we strictly remove such content if we see it on TikTok. More than 40,000 safety professionals are dedicated to keeping our community safe and work diligently to remove harmful content when found," a company spokesperson said.

The NYPD’s Transit and Intelligence Bureau has been working with the city's Department of Education to identify around 70 known subway surfers so they can speak with them and their parents about the dangers. However, officials say the two 14-year-old boys were not known to police.