The man reportedly killed while attempting to ride on top of a Coney Island-bound F train Wednesday has been identified as Christopher Serrano, a Brooklyn native who had gained notoriety as a daring urban explorer and photographer. Serrano, 25, regularly posted photos from off-limits locations across New York City, including the tops of bridges and Manhattan skyscrapers, using the online alias and Instagram handle Heavy Minds.

According to the NYPD, Serrano is believed to have ventured outside of a moving F train car and tried to climb on top of it when he was struck shortly before 5 a.m. yesterday near the Fourth Avenue/Ninth Street station in Park Slope. First responders found Serrano lying dead in the subway roadbed at 5:12 a.m. Police sources told the NY Post that Serrano is believed to have been with a female friend when he attempted to climb on top of the moving car.

It's lonely up here.

A photo posted by NYC | HeavyMinds (@heavy_minds) on

Starting over.

A photo posted by NYC | HeavyMinds (@heavy_minds) on

Nostalgia.

A photo posted by NYC | HeavyMinds (@heavy_minds) on

9/11 Memorial.

A photo posted by NYC | HeavyMinds (@heavy_minds) on

Above the GWB.

A photo posted by NYC | HeavyMinds (@heavy_minds) on

Have a great weekend everyone.

A photo posted by NYC | HeavyMinds (@heavy_minds) on

In the wake of his death, dozens of Serrano's fans and peers within the photography and urban explorer communities have expressed their grief in comments on his Instagram photos. "I keep wanting to wake up now from this horrible dream," one user wrote, while another commented "Rest In Peace homie. Fly hi. Will forever be inspired by your work." Several others have posted tribute photos dedicated to Serrano and his work.

When asked for comment on the collision that resulted in Serrano's death, the MTA did not reply.