Tracy Morgan remained in critical condition Sunday but appeared to show signs of improvement after a car wreck a day earlier that killed another passenger , the comedian 's publicist said . `` He has been more responsive today , which is an incredibly encouraging sign , '' Lewis Kay said . Morgan 's limo van was hit by a tractor-trailer on the New Jersey Turnpike at about 1 a.m. Saturday , according to Sgt . Gregory Williams of New Jersey State Police . Morgan suffered several injuries , including broken ribs , a broken nose , a broken leg and a broken femur . He underwent surgery on his leg on Sunday , Kay said , noting any road to recovery would be a long one . `` We expect him to remain in the hospital for several weeks , '' he said . The chain-reaction wreck killed Morgan 's fellow passenger , comedian James McNair , who performed under the name Jimmy Mack , and injured several others , according to officials . The truck driver charged in the crash has turned himself in , police said Sunday . Kevin Roper , 35 , posted a $ 50,000 bail Saturday night , according to James O'Neill , spokesman for the Middlesex , New Jersey , district attorney 's office . Comedians Ardie Fuqua and Harris Stanton were among the injured , as was Jeffrey Millea , Williams said . One person was released Saturday , but Robert Wood Johnson University Hospital in New Jersey would n't disclose that person 's name . Two others remained in critical condition Sunday , hospital spokeswoman Zenaida Mendez said . CNN reached Fuqua 's agent on Sunday , but he had no comment . Walmart employee charged . Roper is charged with one count of death by auto and four counts of assault by auto after the tractor-trailer he was driving crashed into the limo bus , a statement from Middlesex County Prosecutor 's Office said . Walmart spokeswoman Brooke Buchanan said Roper is an employee . `` This is a tragedy , and we are profoundly sorry that one of our trucks was involved , '' Bill Simon , president and CEO of Walmart U.S. , said in a statement . `` The facts are continuing to unfold . If it 's determined that our truck caused the accident , Walmart will take full responsibility . '' Chain-reaction crash . The wreck occurred about 1 a.m . ET Saturday on the turnpike in Mercer County , Williams said . `` The driver of the tractor-trailer failed to observe slow-moving traffic ahead , '' Williams said . `` At the last minute , he swerved to try and avoid the Mercedes limo bus but struck it from behind , forcing the limo to rotate and overturn . '' Four other vehicles were involved in the crash , the prosecutor 's office said , but no one in those vehicles was injured . Williams said he does not believe alcohol played a role in the crash , but that is under investigation . The National Transportation Safety Board will investigate `` safety issues related to commercial trucking and limousine safety , '' said agency spokesman Keith Holloway . `` All I know is I saw traffic ... and I stopped ... and I was upside down and in the vehicle , '' limo driver Tyrone Gale told WCAU . Gale suffered bruises in the crash , WCAU reported . Christopher Thompson , the co-owner of Atlantic Transportation Services , which was operating the limo bus , said he thought the bus was heading to drop Morgan off in New Jersey . From SNL to '30 Rock ' Morgan , 45 , was a regular on `` Saturday Night Live '' for seven years . He later received an Emmy nomination for his role in `` 30 Rock , '' in which he played Tracy Jordan , an exaggerated version of himself . The New York City native made his reputation with over-the-top characters and impressions of celebrities such as Mike Tyson and Oprah Winfrey . Morgan performed a comedy tour act Friday night at the Dover Downs Hotel & Casino in Dover , Delaware , the venue said . The actor received messages of support and concern on Twitter . `` Wishing a speedy recovery to our friend @ RealTracyMorgan , '' tweeted SNL Weekend Update . `` Shocked to wake up and read that @ RealTracyMorgan is injured . Love to Tracy and wishing him strength , '' said former SNL cast member Rachel Dratch . `` My thoughts are with Tracy Morgan and his family . I hope he pulls through this soon and gets back to making us laugh ! '' said Joan Rivers . `` Saying a prayer for @ RealTracyMorgan , '' said actor-director Jon Favreau . `` Come on @ RealTracyMorgan pull through this buddy , '' tweeted actor Ike Barinholtz of `` The Mindy Project . '' Funny man Tracy Morgan has known fame and foibles .
` ` I saw traffic and I fell and I was upside down , '' limo driver tells Morgan . Morgan remains in critical condition ; truck driver charged in the crash has turned himself in . ' James McNair , also known as ` ` Jimmy " , '' died in the crash .