VIDEO: A teenager who fell 50 feet into a shaft of New York City’s Queensboro Bridge Monday was trying to perform a TikTok challenge, police sources say.

First responders were called to the bridge just before 9 p.m. for a report of a person down a shaft.

The FDNY and the NYPD didn’t know which tower of the bridge the teenager was in when they started searching for him, but firefighters eventually discovered a shoe and blood near an open hatch.

Firefighters had to use ropes and harnesses to get into the shaft and rescue the teenager. He was pulled out just before 11 p.m. and was taken to a local hospital in critical condition.

“Just mumbling from the severe trauma,” FDNY firefighter Khalid Lee said. “The adrenaline that was felt, it was, it was moving, but this is what we train for.”

In fact, those firefighters say just 30 minutes before the call came in, they had been training on how to rescue a victim from a hole.

According to NYPD sources, the 16-year-old boy told police he was with friends on the bridge, but they left him after he fell.

WCBS-TV CBS 2 New York City