By Steve Patterson, Matt Rivers

CRANBURY TOWNSHIP, N.J. (CBS) — The driver of the truck that caused a six-vehicle accident on the New Jersey Turnpike Saturday morning, leaving actor and comedian Tracy Morgan among others critically injured, has been charged.

According to New Jersey State Police, the accident happened around 1 a.m. in the northbound lanes of the Turnpike at mile post 7A near Cranbury Township, New Jersey.

Police say it appears that accident happened when a limousine carrying Morgan and six other people was struck from behind by a tractor-trailer, then overturned.

Police say the driver of the truck, 35-year-old Kevin Roper from Georgia, was charged Saturday evening with causing the accident.

Kevin Roper (credit: Middlesex County Prosecutor’s Office)

Kevin Roper (credit: Middlesex County Prosecutor’s Office)

Authorities say Roper failed to notice traffic slowing down in front of him. He was charged with one count of death by auto and four counts of assault by auto.

VIEW: Exclusive Photos From Scene

Police confirmed one person died and four others were injured, including Morgan, in the pile-up. Only the people inside Morgan’s limo were hurt.

The 45-year-old Morgan, along with 37-year-old Jeffery Millea, were airlifted to Robert Wood Johnson University Hospital in New Brunswick, New Jersey where they are being treated in the Intensive Care Unit.

Morgan’s publicist, Lewis Kay, issued the following statement on Sunday:

“While Tracy remains in critical condition, he has been more responsive today, which is an incredibly encouraging sign. He sustained a number of injuries including a broken leg, a broken femur, a broken nose and several broken ribs. He had surgery earlier today on his leg. We expect him to remain in the hospital for several weeks. His family is tremendously overwhelmed and appreciative of the outpouring of love and support from his fans. We will continue to update his status when new information becomes available.”

READ: Celebrities Offer Thoughts, Prayers To Tracy Morgan

State police identified the person who was killed in the crash as James McNair, 63, of Peekskill, New York. He was also a comedian.

A fourth man, Ardie Fuqua Jr., is also in critical condition. Two other people were inside the limo during the accident, but they were uninjured.

Morgan, a former ‘Saturday Night Live’ and ’30 Rock’ star, was returning from a show at The Rollins Center at Dover Downs in Delaware at the time of the accident.

Roper had bail set at $50,000 early in the day Saturday. He  surrendered to police on Sunday.

Walmart U.S. President and CEO Bill Simon issued the following statement:

“We’re praying for the family and friends of the passenger who lost his life in the terrible accident in New Jersey. 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.  

This is a tragedy and we are profoundly sorry that one of our trucks was involved. We are working quickly to understand what happened and are cooperating fully with law enforcement to aid their investigation.

The facts are continuing to unfold. If it’s determined that our truck caused the accident, Walmart will take full responsibility.

Safety is our absolute highest priority, but that is no comfort whatsoever to the families and friends who are suffering today. We offer them our deepest condolences. We can’t change what happened, but we will do what’s right for the family of the victim and the survivors in the days and weeks ahead.”

The NTSB will be joining state police in the investigation.