(CBS/AP)-- A tour bus driver behind the wheel in a horrific crash that killed 15 people last year was found not guilty of manslaughter and criminally negligent homicide on Friday.
Ophadell Williams was found guilty on one count of aggravated unlicensed operation of a motor vehicle.
Williams wept and covered his face with his hands as the verdict was read. On the count which he was found guilty, the judge sentenced him to 30 days in prison, which he has served. He also was ordered to pay a fee of $500.
Williams argued throughout the trial that he had been awake and alert, and said the crash was not the result of reckless behavior or extreme exhaustion. He said a tractor-trailer cut him off, causing him to swerve and hit a guardrail. But investigators could find no indication that had occurred.
His lawyer had said he was wracked with guilt over the crash — but not guilty of manslaughter.
"It happened as a motor vehicle accident, not as some crime," said Williams' lawyer, Patrick Bruno. "He tried to avoid tragedy, and tragedy occurred."
Bronx Assistant District Attorney Gary Weil had alleged Williams was so sleep deprived from working another job during the day that it affected his reflexes the same as if he were intoxicated behind the wheel. He said Williams knew the risks, but drove anyway.
The trial lasted more than eight weeks, with Superstorm Sandy causing a delay. Jurors deliberated about a week, but not consecutively.
The March 12, 2011, crash happened on Interstate 95 at daybreak as Williams was ferrying a busload of gamblers to Manhattan's Chinatown from the Mohegan Sun casino in Uncasville, Conn. The bus crashed just feet from a road sign that read: "Welcome to the Bronx."
The bus struck a guard rail, toppled over and hit a signpost that tore open the top before skittering to a stop.
The victims were mostly Chinese men and women over the age of 40 who were regulars at casinos. About half died. The others were injured. Survivors missing limbs testified in court, including Ren Xiang Yao who spoke of how he lost both arms when he raised them up instinctively when the bus crashed. He said he didn't see the crash — though he remembers when the rescue crews arrived.
"I used all the energy I had left and said, 'I'm here, I'm here, please come rescue me,'" he said. "By the time I woke up, I was already in the hospital."
Yao was hospitalized for nearly a month and had several operations.
Jurors also watched video from the scene of the accident and other wounded passengers who testified the bus was unsteady in the moments before it crashed.
Williams has been held in Rikers Island because his family cannot post $250,000 bail. He faced a maximum of 7 1/2 years to 15 years in prison.
The National Transportation Safety Board said in June that the accident was probably caused by driver fatigue, and a bus company that provided too little safety oversight. It stopped short of saying Williams had fallen asleep.
Williams worked for World Wide Tours of Greater New York. Federal regulators shut down the bus operator after the accident for safety violations. Williams had not turned in any driver's logs while working for the company as required by federal safety regulations, yet World Wide took no action, federal investigators said.
But the bus company won't face any criminal charges related to the crash, Bronx District Attorney Robert T. Johnson has said.
New York state has stepped up inspections of tour buses since the crash. Dozens of buses have been taken out of service after police found problems with logbooks, licenses or equipment. But there have been several bus accidents since.