The 45-year-old '30 Rock' star was returning from a concert in a limo bus when the accident occurred in Mercer County, CNN reported quoting Sgt Gregory Williams of the New Jersey State Police.
The limo bus overturned after it was rear-ended by a tractor-trailer. Two tractor-trailers, two cars, an SUV and the limo bus were involved in the accident.
"The limo bus is the only vehicle that overturned. Looks like one of the tractor-trailers may have rear-ended that limo bus, but that's preliminary at this time," Williams said.
Williams ruled out alcohol as a factor in the crash at this point.
The four injured were being treated at the Robert Wood Johnson University Hospital. Peter Haigney, a spokesman for the hospital said that a man named Tracy Morgan was among those in critical condition, but citing privacy laws, declined to confirm it is the actor.
State police confirmed his identity to CNN.