BMX Star T.J. Lavin in Coma After Major Crash

Lavin was competing in a Dew Tour event in Las Vegas -- when he hit a dirt ramp, lost control, and slammed down onto the ground. Friends and crew workers immediately rushed to Lavin's side, but he didn't appear to be moving.

Lavin was rushed to nearby University Medical Center hospital ... where he was placed into a medically induced coma.

We're told Lavin is also experiencing brain swelling and is listed in critical condition.

UPDATE: A rep for MTV tells us, “Our thoughts are with TJ. He is an important part of MTV’s extended family and we’re all praying for him."

T.J. Lavin needs your prayers.
The BMX star and host of MTV's The Challenge crashed his bike during an event in Las Vegas last night and was rushed to the hospital. He is experiencing brain swelling and has been placed in a medically induced coma.
Lavin's vehicle hit a dirt ramp and lost control during the accident, as crew workers rushed to the star's side. He is listed in critical condition.