The driver of a Wal-Mart tractor-trailer that slammed into a limo carrying comedian Tracy Morgan last June had been awake more than 28 hours, the National Transportation Safety Board said today. 
 
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 Around 1 a.m. on June 7, 2014, 35-year-old Kevin Roper – then halfway through the 13th hour of his 14-hour shift – slammed into Morgan’s limo from behind, killing comedian James McNair and seriously injuring Morgan and three others. 
 
 Before starting his Wal-Mart shift, Roper had driven 12 hours in his personal vehicle from his home in Georgia to his base in Delaware, according to the NTSB. 
 
 His “decision to drive 800 miles overnight” was “a factor in the crash,” NTSB senior accident investigator Dennis Collins said today. 
 
 Though Wal-Mart provided fatigue information during its driver training, it was not required to have a fatigue management program,the NTSB said. 
 
 Moments before the crash, the trailer was traveling at 65 mph, 20 mph over the construction zone’s 45 mph speed limit. 
 
 “Had the truck driver been traveling at the posted work zone speed limit of 45 mph, it could have been stopped before impact,” NTSB investigator David Rayburn said today. 
 
 Roper's attorney told ABC News he would dispute the NTSB's conclusions. 
 
 The passengers in the rear of the limo’s rear compartment were not wearing seatbelts at the time of the crash, NTSB chairman Christopher Hart announced at a board meeting today, nor had they received a safety briefing outlining the benefits of seat belts. 
 
 After being hit by the Wal-Mart truck, the limo then struck three other vehicles and rolled over before coming to rest on its side on the New Jersey Turnpike. 
 
 Because the limo had been customized, “the passengers had no available exits until emergency responders removed parts of a plywood panel that had been installed,” Hart said today. 
 
 Indeed, it took nearly 40 minutes for first responders to extricate some of the victims from the limo. 
 
 “I shudder to think what would have happened if this vehicle had caught fire,” NTSB board member Robert Sumwalt noted. 
 
 Roper was later charged with one count of vehicular homicide and several counts of assault by auto, with authorities saying they believed he had dozed off behind the wheel. He pleaded not guilty. 
 
 The crash left Morgan, then 45, in critical condition, with multiple broken bones and a traumatic brain injury. 
 
 Since then, the comedian has “struggled” to regain his old self, his lawyer said. 
 
 In a June 2015 interview with “Today” anchor Matt Lauer, Morgan wondered through tears whether he was ever “going to be funny again.” 
 
 He filed a civil suit against Wal-Mart; they reached a confidential settlement in May. 
 
 The retailer, which initially faulted Morgan and his colleagues for not wearing seat belts, later “took full responsibility for the accident,” according to Morgan’s lawyer. ||||| WASHINGTON (AP) — A Wal-Mart truck driver who hadn't slept in 28 hours failed to slow down despite posted warning signs and was responsible for a highway crash last year that severely injured comedian Tracy Morgan and killed another comedian, the National Transportation Safety Board said Tuesday. 
 
 FILE - In this April 9, 2014, file photo, actor Tracy Morgan attends the FX Networks Upfront premiere screening of "Fargo" at the SVA Theater in New York. The National Transportation Safety Board is meeting... (Associated Press) 
 
 National Transportation Safety Board (NTSB) Chairman Christopher Hart speaks during an NTSB meeting at their headquarters in Washington, Tuesday, Aug. 11, 2015, to determine the cause of an accident last... (Associated Press) 
 
 An accident description is displayed on a large screen as the National Transportation Safety Board (NTSB) meets at their headquarters in Washington, Tuesday, Aug. 11, 2015, to determine the cause of... (Associated Press) 
 
 But the board said the failure of Morgan and other passengers in a limousine-van to wear seat belts and adjust headrests contributed to the severity of injuries when the limo was struck from behind by the truck. 
 
 Most of their injuries were caused when the passengers were whipped around or thrown into the sides of the vehicle, the board said at a meeting to determine the cause of the crash and make safety recommendations. 
 
 None of the passengers in the back of the 10-seat limo or the driver was wearing a seat belt. 
 
 The board said truck driver Kevin Roper of Jonesboro, Georgia, could have prevented the June 7, 2014, crash if he had slowed to 45 mph, the posted speed limit for the construction work zone on the New Jersey Turnpike near Cranbury, where the crash occurred. 
 
 The truck traveled 0.9 miles past the first work zone sign and more than 0.4 miles past the 45 mph speed limit sign without slowing from 65 mph. The truck was going that fast until it reached a closing distance of approximately 200 feet before the impact. 
 
 At 45 mph, the truck could have stopped before impact, the board concluded. 
 
 The collision with the limo started a chain reaction crash that affected 21 people in six vehicles. 
 
 "One tragic aspect of roadway deaths is that so often they could have been prevented," said the safety board's chairman, Chris Hart. 
 
 Heavy trucks are involved in nearly 1 in 8 fatal crashes, NTSB said. In work zones, 1 in 4 fatal crashes involves a heavy truck. 
 
 Roper had driven over 800 miles overnight from Georgia to a Wal-Mart distribution center in Delaware to pick up a load before starting the trip without stopping for sleep. 
 
 He had worked for Wal-Mart for 15 weeks and had had nine "critical event reports." Critical event reports, which are generated by a truck's computers and downloaded by Wal-Mart, record things such as hard braking, activation of the vehicle's stability control system or other events that might indicate unsafe driving. 
 
 Roper also had been involved in a preventable accident, causing him to lose his safety bonus, investigators said. 
 
 Wal-Mart had provided guidance to its drivers on preventing fatigue, but didn't have a comprehensive program to prevent drivers from being assigned over-tiring schedules or to make sure they were rested before reporting to work, the board said. Since then, Wal-Mart has taken greater steps to educate drivers about fatigue and has said it will put in place a program to reduce fatigue, investigators said. 
 
 The board has long raised concerns about operator fatigue leading to accidents across all modes of transportation, from airline pilots to train engineers. 
 
 Investigators said the limo wound up on its side with its rear doors jammed shut. A sheet of plywood that had been added to the limo to separate the cab from passengers blocked occupants from escaping the vehicle through the front doors after the crash. 
 
 It took emergency responders working with the assistance of other motorists 37 minutes to remove the first of the crash victims from the rear of the limo. 
 
 Investigators said emergency responders, mostly volunteers, didn't have the training to address some of the logistical and coordination issues arising from the complicated accident. New Jersey doesn't have requirements for the number of training hours that volunteer emergency responders must have, or a certification program, they said. 
 
 Comedian James "Jimmy Mack" McNair of Peekskill, New York, a mentor of Morgan's, was killed. Morgan suffered head trauma, and was in a coma for two weeks. Three other passengers in the limo suffered serious injuries. 
 
 Morgan, a former "Saturday Night Live" and "30 Rock" star, and the others were returning from a show in Dover, Delaware. 
 
 Roper was charged with death by auto and four counts of assault by auto in state court in New Jersey. 
 
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– How are your reflexes after you've been awake for 28 straight hours? The NTSB says the driver of the truck that smashed into Tracy Morgan's limo was in that exact predicament, reports ABC News. Kevin Roper, 35, drove 800 miles from his home in Georgia to Delaware, where he got into his Walmart truck and embarked on a 14-hour trip, say NTSB investigators. In the 13th hour of that trip, Roper hit Morgan's vehicle on the New Jersey Turnpike, killing one passenger and injuring Morgan and three others. In addition to driver fatigue, the NTSB also notes that Roper was doing 65 in a construction zone, 20mph over the limit, reports AP. “Had the truck driver been traveling at the posted work zone speed limit of 45mph, it could have been stopped before impact,” says NTSB investigator David Rayburn. The agency also says that neither Morgan nor the other passengers in the limo van were wearing seatbelts, which likely made their injuries worse. (Walmart has settled with Morgan, who vows to make people laugh again.)