The Wal-Mart truck driver accused of triggering a crash that critically injured actor and comedian Tracy Morgan and killed another comedian had not slept for more than 24 hours, a criminal complaint said.

A court official on Monday said 35-year-old Kevin Roper is scheduled to face an initial court appearance on Wednesday. He remains free after posting $50,000 bond. Roper is charged with death by auto and four counts of assault by auto.

Authorities said Roper apparently failed to slow for traffic ahead early Saturday in Cranbury Township and swerved at the last minute to avoid a crash. Instead, his big rig smashed into the back of Morgan's chauffeured Mercedes limo bus, killing comedian James "Jimmy Mack" McNair, authorities said.

According to the criminal complaint, Roper was operating the truck "without having slept for a period in excess of 24 hours resulting in a motor vehicle accident." It doesn't specify the basis for that assertion.

Also critically injured in the crash were Morgan's assistant, Jeffrey Millea, 36, of Shelton, Conn., and comedian Ardie Fuqua Jr., 43, of Jersey City. They remained in critical condition Sunday evening, said Zenaida Mendez, a spokeswoman for Robert Wood Johnson Hospital in New Brunswick. Another passenger, comic Harris Stanton, was treated and released.

Tracy Morgan is recovering but is expected to remain hospitalized for several weeks after having surgery on a broken leg suffered in the chain-reaction crash on the New Jersey Turnpike.

The 45-year-old actor and comedian, a former Saturday Night Live and 30 Rock cast member, remained in critical condition early Monday. Morgan's spokesman, Lewis Kay, said he was "more responsive" Sunday after having surgery for a broken leg.

Kay said Morgan also suffered a broken femur, a broken nose and several broken ribs and is expected to remain hospitalized for several weeks. He said Morgan's family is "tremendously overwhelmed and appreciative of the outpouring of love and support from his fans."

Trucking regulations questioned

Wal-Mart President Bill Simon said in a statement that the company "will take full responsibility" if authorities determine its truck caused the accident.

The National Transportation Safety Board is working with state police to look at any issues in the crash related to commercial trucking and limousine safety.

'This is part of a systemic problem of having tired people driving at night and driving large trucks.'- Henry Jasny, vice-president of Advocates for Highway and Auto Safety

Federal regulations permit truck drivers to work up to 14 hours a day, with a maximum of 11 hours behind the wheel. The other time is usually devoted to loading and unloading and paperwork. They must have a minimum of 10 hours off between work shifts to sleep. Drivers can work a maximum of 60 or 70 hours per week, depending upon the type of company they work for.

Safety advocates said they hope the accident in New Jersey will help their case.

"This isn't an aberrant or unusual thing that just sort of happened for no reason," said Henry Jasny, vice-president of Advocates for Highway and Auto Safety. "This is part of a systemic problem of having tired people driving at night and driving large trucks.”

But Dave Osiecki, vice-president of the American Trucking Association, said no regulations can prevent a driver from making "bad choices."

'I couldn't reach them,' driver says

Tyrone Gale, who was driving the limo bus, told ABC News that he was disoriented after the vehicle flipped over and could hear Morgan yelling for help.

APTOPIX Tracy Morgan Accident

In this image from video, the limousine bus carrying Tracy Morgan and six other people lies on its side on the New Jersey Turnpike. State and federal officials continued their investigation of the six-vehicle crash. (Will Vaultz/ Associated Press)

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

Roper, accompanied by his attorney, turned himself in to state police. He was released on $50,000 bail Saturday night and has been placed on administrative leave, Wal-Mart spokesman David Tovar said Sunday.

Wal-Mart President Bill Simon said in a statement that the company "will take full responsibility" if authorities determine its truck caused the accident.

The National Transportation Safety Board is working with state police to look at any issues in the crash related to commercial trucking and limousine safety.

Morgan, a New York City native, was returning from a standup performance at Dover Downs Hotel & Casino in Delaware when the crash occurred. In all, six vehicles were involved in the pileup, but no one from the other cars was injured.

'We're hoping for the best'

At a press event Saturday in Los Angeles to promote the upcoming comedy film Think Like A Man Too, cast members, many of whom have worked with and are friends with Morgan, wished him well.

Kevin Hart said he owes much of his success to Morgan, crediting him for paving the way for comics like himself to become successful.

"We just want him to get better and to get back to everyone that loves him and get back to doing what he does best, making people laugh," Hart said.

'We just want him to get better and to get back to everyone that loves him and get back to doing what he does best, making people laugh.'- Kevin Hart, comic

Fuqua's mother, Doris, said she visited him in the hospital Saturday. The writer-comedian had toured with Morgan for nearly a year, she said, and had opened for him Friday night.

"We're hoping for the best," Doris Fuqua said Sunday, adding that she didn't know how long he may be hospitalized. "It's too early to tell."

McNair, 62, of Peekskill, N.Y., was a close friend and mentor to Morgan, Morgan's ex-wife, Sabina Morgan, told the New York Daily News. "He was one of the first comedians that took Tracy under his wing," she said.

Royale Watkins, a Los Angeles-based comedian who said he had performed in New York clubs with Morgan and McNair, described McNair as having a big personality.

"There may be guys like Tracy who get the fame and notoriety, but you have people like Jimmy Mack who have kind of energized and fuelled cats like Tracy and kept them going on the road," Watkins said.