WASHINGTON, D.C. — Not enough sleep and speeds close to 90 mph were cited by the National Transportation Safety Board as the causes of a motorcoach accident on Jan. 6, 2008, in Mexican Hat, Utah.

The crash killed nine passengers and injured 43 others.

"This tragic accident was entirely preventable," said NTSB Acting Chairman Mark Rosenker. "More importantly, it shines a spotlight on the need for all motor vehicle operators to take responsibility for their physical fitness before they get behind the wheel."

The NTSB also concluded that driver hours-of-service violations, motor carrier trip planning, motorcoach occupant protection, and emergency medical notification and response with regard to large motorcoaches traveling on rural roads  combined to cause the accident.

A convoy of 17 motorcoaches was returning to Phoenix after a three-day ski trip in Telluride, Colo., when bad weather forced the drivers to reroute through San Juan County, Utah. One of the drivers, 71-year-old Welland Lotan, who had been previously diagnosed with sleep apnea, lost control of his bus and began to run off the road. The motorcoach overturned, resulting in the roof being torn off and 51 of the 53 passengers beibng ejected from vehicle.

Improved motorcoach roof strength has been a part of the NTSB’s lost of Most Wanted Safety Improvements for the past 10 years.