[Update Below] A 'subway surfer' was injured today after falling off the train on the Upper East Side. According to the MTA, the incident occurred around 12:12 p.m. at the 96th Street station at Lexington Avenue and 96th Street. A spokesperson says preliminary information indicates he was subway surfing on the 6 train and he fell between cars. He has been taken to Metropolitan Hospital with head injuries.

Police add that the investigation is ongoing. Southbound 6 service is running express from 125th Street to Grand Central right now. We'll update with any more information as it becomes available.

Update: Police say the 45-year-old man was riding on top of the 6 train when he fell and hit his head on a steel beam.

Update: According to the News, the 45-year-old man who fell off the train was a homeless man who friends call "Grumps." And he was reportedly smoking synthetic marijuana, K2, before climbing onto the train. "He was hanging out getting high," said Pablo Reyes, who identified himself a friend. "I told him, ‘Stop getting high off that s**t. It ain’t no good for you. He probably was hallucinating."

“He was standing up with his hands open,” Reyes added. “He saw the beam coming. He laid down. He tried to duck down. It opened his head right up.“ Reyes said Grumps had been panhandling earlier in the day, and has been homeless for about a year.

Update: The News now reports that the man who fell off the train has died.