Police say they found two people, including a 13-year-old girl, dead at the Marcy Avenue and Broadway train station in Williamsburg early Saturday morning.

Sources say authorities are investigating it as a possible subway surfing incident.

Video shows first responders on the scene just after 3 a.m.

According to police, the 13-year-old and another female were found on top of the train.

Neighbors told News 12 the J train is a popular line for subway surfing.

The identities or the age of the other victim was not immediately known.

Police had not confirmed as of Saturday afternoon whether the two were subway surfing. They said they are investigating the incident as two people found dead on arrival.