An attorney for the Canadian travel company whose bus crashed and killed nine passengers in Oregon says the driver had more than seven hours of sleep the night prior to the accident.
Mark Scheer -- attorney for Mi Joo Tour & Travel -- says black ice was a factor in the Dec. 30 crash near Pendleton, Ore. The crash left 38 people injured, including the driver.
"With respect to Mi Joo Tours, they have no prior history of bus accidents involving passenger injury or injury to other members of the public," said Scheer. "Mi Joo continues to fully cooperate with all authorities and the pending investigations. Mi Joo's primary concern at this time is working to assist the passengers and family members affected by this tragic accident".
Scheer's comments come a day after the U.S. Department of Transportation revoked the travel company's authority to provide passenger service in the United States after determining a driver was not properly rested when his bus crashed.
A federal investigation found that driver Haeng Kyu Hwang had been on duty for 92 hours in the eight-day stretch before the tragedy, exceeding the 70-hour federal limit.
The official cause of the crash remains under investigation.
Copyright 2013 KPTV (Meredith Corporation.) All rights reserved. The Associated Press contributed to this report.