Tracy Morgan -- Critical Condition After Fatal Car Accident (UPDATE)

Tracy Morgan was in a horrific 6-vehicle accident early Saturday morning in New Jersey and is now fighting for his life.

Morgan was riding in a limo bus on the NJ Turnpike after a concert ... when it was rear-ended by a tractor-trailer -- at least that's the way it now appears. Tracy's limo overturned in the wreck.

One person in the limo was killed, and three others are in critical condition, including the former star of "SNL" and "30 Rock."

Police say 2 tractor-trailers, 2 cars, an SUV and the limo bus were involved in the chain collision -- and, at this point, they do not believe alcohol was a factor in the crash.

Tracy had a standup gig Friday night in Delaware and was on his way home when the accident happened.

Another comedian was riding with Tracy last night -- Ardie Fuqua was the opening act in Delaware. Ardie tweeted pics of Tracy on stage and of himself standing next to the bus. In a Facebook post he wrote, "We traveled back to NYC in style in a luxury Mercedes Sprinter. Road life is a good life!"

That was posted roughly 30 minutes before the accident. According to reports, Fuqua is also in critical condition.

The single fatality was a 63-year-old named James McNair.