The lawyer for a Vancouver bus company involved in a deadly Oregon crash says black ice, not driver fatigue, was responsible for the tragedy.

Nine people died and 38 were injured Dec. 30 when the tour bus owned by Mi Joo Tour & Travel Ltd. crashed near the northeast Oregon community of Pendleton.

"Black ice was a significant factor in the cause of the accident," said Scheer Wednesday evening. "It appears that the area in question near Pendleton, Ore., ... has a history of traffic incidents, and there were other accidents in the area close to this one involving black ice on Dec. 30, 2012."

The U.S. Department of Transportation on Tuesday pulled the company's authority to operate saying it had determined the bus driver had spent 92 hours operating the bus over the eight-day trip.

Scheer says the bus driver had about seven and one-half hours of sleep the night before the crash, and that morning had only been on the road for about two and one-half hours, including a rest break.

He says the bus driver had a good safety record, is in good health, doesn't use alcohol or tobacco, and there is no evidence to suggest alcohol or drugs played any role in the crash.

Two of the surviving passengers have filed a lawsuit in Washington against the bus company, alleging the driver should legally not have been behind the wheel due because he had worked too many hours.