The Wal-Mart truck driver charged in the fatal wreck that left comic Tracy Morgan critically injured had not slept for 24 hours before the crash, authorities in New Jersey said Monday.

Kevin Roper, 35, faces charges including death by auto and four counts of assault by auto. He is free on $50,000 bail and faces a court hearing Wednesday, the Middlesex County Prosecutor's Office said.

State Police said Roper, of Jonesboro, Ga., failed to see a traffic slowdown on the New Jersey Turnpike near Cranbury Township early Saturday. His truck slammed into a limousine bus carrying Morgan, James "Jimmy Mack" McNair and several others, setting off a chain-reaction crash involving another tractor-trailer, an SUV and two cars, authorities said.

All the victims were in the limo bus. Morgan mentor McNair, 62, was killed. Morgan friend Jeffrey Millea, 36, and comedian Ardie Fuqua Jr., 43, were critically injured, while comic Harris Stanton was treated and released from a hospital Saturday.

The limousine had been returning from a stand-up comedy show in Delaware. Tyrone Gale, who was driving the limo bus, told ABC News his vehicle flipped over.

"I climbed around and heard Tracy screaming for help," Gale told ABC. "I climbed up on the body of the limo bus … but I couldn't reach them."

Morgan, 45, was airlifted to Robert Wood Johnson Medical Center in nearby New Brunswick, N.J. His spokesman, Lewis Kay, said Morgan was "more responsive" Sunday, though still critically injured.

Morgan, who starred in 30 Rock and Saturday Night Live, suffered broken leg bones, a broken nose and several broken ribs, Kay said

"We expect him to remain in the hospital for several weeks," Lewis Kay said. "His family is tremendously overwhelmed and appreciative of the outpouring of love and support from his fans."

Morgan, a New York City native, worked on SNL from 1996 to 2003. He joined the cast of NBC's comedy 30 Rock in 2006, receiving an Emmy nomination for best supporting actor in 2009.

Contributing:; Associated Press