Passenger Recounts Chaos of Casino Bus Crash on I-95 When Truc Thanh Tran boarded a World Wide Travel bus after a night at the Mohegan Sun casino in Connecticut, she wanted to sit in a front row but was sent to the back by a ticket-taker, she recalled on Friday. It was a seat assignment that might have helped save her life. Ms. Tran, a Vietnamese immigrant who speaks little English, said she was asleep in the back when the bus struck a guardrail, flipped over and plowed front-first into a signpost that sheared off the roof in a crash that killed 15 passengers on March 12, 2011. "I heard people yelling and crying," Ms. Tran, 45, said haltingly through a translator in State Supreme Court in the Bronx. I was awake and I saw people dying. Ms. Tran testified during the fourth day in the trial of the bus driver, Ophadell Williams, who has been charged with manslaughter and criminally negligent homicide in the crash, on Interstate 95 in the Bronx. Mr. Williams's lawyer, Patrick L. Bruno, has sought to portray Mr. Williams as a hard-working man who lost control of the bus after being cut off by a tractor-trailer and, despite his own injuries, tried to help injured passengers from the wreckage. But prosecutors have disputed that there was a tractor-trailer, and instead countered that Mr. Williams was exhausted from lack of rest and that he drove erratically before the crash. On Friday, Gary Weil, an assistant district attorney, showed a 55-minute video of the aftermath of the crash: flattened guardrails and crushed fiberglass bus parts, a blood-splattered metal pole and shoes and cellphones strewed all over the bus. "There was a lot of ringing from cellphones," recalled George MacLarty, a senior investigator for the State Police, who said the bodies had been removed before the video was shot. After striking the guardrail, the bus traveled 531 feet, the last 100 on its side after it flipped over, Investigator MacLarty said. The pole sliced through three-quarters of the bus, shearing off the roof, according to prosecutors. Afterward, Florence Wong said outside the courtroom that she had been looking for any sign of her father, Don Lee, who was killed in the crash. She thought she might have caught a glimpse of his shoes in the video, but was not certain. "I can't imagine how scared the people were on the bus," she said. Ms. Tran, who lives in Brooklyn, told the jury that the man seated next to her had died in the crash and that she was unable to move at first and had to be lifted out of the wreckage by rescue workers. Since then, she testified, she has continued to suffer from pain in her back and right arm. "I was so much in pain I could not cook and I did not want to get up and do anything," she said. But Mr. Bruno sought to show in his cross-examination that Ms. Tran's injuries were minimal, suggesting that she was trying to support her claim against Mr. Williams and the bus company in a lawsuit. Prosecutors have said seven passengers were seriously injured in the crash, including one man whose arms were ripped off as he tried to shield his head, and several others who sustained severe head injuries and bone fractures.