A truck driver from Georgia has been charged with death by auto in connection with a crash on the New Jersey Turnpike that killed one man and injured four others, including actor and comedian Tracy Morgan.

Middlesex County prosecutors say 35-year-old Kevin Roper of Jonesboro also faces four counts of assault by auto stemming from the crash, which occurred around 1 a.m. local time Saturday. His bail was set at $50,000.

Roper's tractor-trailer allegedly rammed into a chauffeured limousine bus that Morgan was riding in. That set off a chain-reaction crash that left one member of his entourage dead and two others seriously hurt.

Morgan and the two others remained hospitalized in critical condition Saturday night.

The former Saturday Night Live and 30 Rock cast member was returning from a standup comedy show in Delaware when his Mercedes limo bus carrying seven people overturned on the New Jersey Turnpike near Cranbury Township at about 1 a.m., state police Sgt. 1st Class Greg Williams said.

James McNair, 62, of Peekskill, New York, a passenger in the limo bus, died at the scene, Williams said. Morgan, 45, and Jeffrey Millea, 36, of Shelton, Connecticut, were flown from the accident scene to Robert Wood Johnson Hospital, where they remained in critical condition, hospital spokesman Peter Haigney said.

A fourth passenger, comedian Ardie Fuqua Jr., was also in critical condition at the hospital, while a fifth passenger, Harris Stanton, was treated and released, Haigney said. Two others in the limo were uninjured, Williams said.

Morgan's publicist said the comedian's loved ones have joined him at the hospital, where he remains in the intensive care unit.

"His family is now with him and he is receiving excellent care," spokesman Lewis Kay said in a statement. "We don't anticipate much of a change in his condition today but will provide a further update once more information becomes available."

Williams said the tractor-trailer driver apparently failed to notice slow traffic ahead and swerved at the last minute in a vain attempt to avoid a crash. But it smashed into the back of the limo, prompting a chain-reaction crash that also involved a second tractor-trailer, an SUV and two cars.

Police say the vehicle carrying the 45-year-old former Saturday Night Live and 30 Rock cast member and six others was involved in a six-vehicle accident on a New Jersey turnpike early this morning. (Richard Clement/Reuters)

The Middlesex County Prosecutor's office was investigating and planned to release a statement later Saturday.

Morgan's limo was owned by Atlantic Transportation Services, which had two employees on board: one driving and one in the front passenger seat.

"Although the investigation is still pending, we concur with the preliminary reports that the accident was caused by another vehicle travelling behind the Atlantic limo bus," the Rehoboth Beach, Delaware-based company said. "We are grateful that our drivers did not sustain life-threatening injuries."

Walmart President Bill Simon issued a statement that said one of the firm's trucks was involved in the accident. While noting that the crash remains under investigation, Simon said "Walmart will take full responsibility" if authorities determine that the company's truck caused the accident.

"We're praying for the family and friends of the passenger who lost his life in the terrible accident" the statement said. "Our hearts go out to everyone involved and we hope those who were injured get the care that they need and make a full recovery."

Morgan performed comedy standup Friday night at Dover Downs Hotel & Casino in Delaware. His scheduled appearance at the Fillmore Charlotte in North Carolina on Saturday night has been cancelled.

Fuqua had tweeted that he was opening for Morgan on Friday. On his Instagram page, Fuqua included a collage of photos from the Delaware show.

"This is what it looks like from the stage to see a standing ovation from 1500 people," Fuqua wrote at around midnight Friday. "Then we travelled back to NYC in style in a luxury Mercedes Sprinter. Road life is a good life!"

Difficult childhood

The 45-year-old New York City native joined SNL in 1996 and was on the sketch-comedy program for seven years before leaving to star in The Tracy Morgan Show in 2003. That show lasted just one season. In 2006, Morgan found a long-running role on NBC's hit show 30 Rock, which was created by SNL co-star Tina Fey. He received an Emmy nomination for best supporting actor for 30 Rock in 2009.

One of his signature routines on 30 Rock involved an award category his character invented called an "EGOT," representing all the entertainment-related awards he hoped to win: an Emmy, a Grammy, and Oscar and a Tony.

Morgan grew up fatherless, one of five siblings, in a blighted section of Brooklyn, where he helped raise and support the family.

He once called his gift for being funny "a defence mechanism" for his miserable circumstances. As a teen, he started doing comedy on the streets to supplement the family's welfare income.

His tough upbringing informed his humour.

"My aunt was a crackhead," he told his Brooklyn audience in a recent special aired on Comedy Central. "I remember one Christmas she bought me a Game Boy. Then she stole it. Then she helped me look for it."

In recent years, he has struggled with alcoholism and has been arrested on drunken driving charges. He had a successful kidney transplant in late 2010.

Morgan's films include Jay and Silent Bob Strike Back, The Longest Yard, First Sunday, Rio and Why Stop Now.

The New Jersey Turnpike was closed for more than five hours after the crash.