WASHINGTON (AP) -- Safety investigators said Tuesday that a bus was traveling 88 to 92 miles per hour when it crashed last year in Utah, killing nine and injuring 43 others. Driver fatigue was likely the root cause of the crash, they said.

Investigators told the National Transportation Safety Board that the bus driver, Welland Lotan, who was 71 at the time, suffered from sleep apnea, but used a device to regulate his breathing while sleeping.

Related:

NTSB cites safety agency as factor in bus crash

A federal safety board is citing driver fatigue as the cause of a Utah bus crashed that killed nine and injured 43 others, but blames inaction by another safety agency for the severity of the accident.

Lotan also reported having head congestion for three days prior to the accident, which was probably the result of altitude sickness or a cold and which likely interfered with his sleep, investigators said.

"It's really tragic -- tragic in loss of life, tragic in the injuries people suffered and tragic because, in my judgment, this accident was preventable," board member Kitty Higgins said.

The motorcoach was carrying 52 passengers returning to Phoenix from a ski vacation in Telluride, Colo., on Jan. 6, 2008 when it rounded a bend on a remote two-lane highway near the town of Mexican Hat, careened off the side of the road and rolled down an embankment.

Investigators said it is likely the driver's fatigue caused him to misjudge the bus' speed. The speed limit on that stretch of highway was 65 mph.

The bus was part of a charter of 17 motorcoaches carrying 800 people. Lotan had risen at 6:45 a.m. MST that morning and told passengers and others that he was fatigued and had been feeling sick for three days, investigators said. He had effectively been working since 10 a.m., when he attended drivers' meeting and then helped put chains on tires and refuel buses, they said.

When the accident occurred at 8:02 p.m., Lotan had been driving nearly five hours. Federal regulators limit commercial drivers to a maximum 15 hours on duty and 10 hours actual driving.

Investigators were able to determine the speed using video from cameras installed on the bus. Audio equipment on the bus also recorded a passenger yelling "slow down" to the driver.

The roof of the motorcoach was sheared off in the accident and everyone was thrown out except Lotan, who was wearing the only seat belt on the bus, and one passenger, whose leg got stuck.

The board recommended a decade ago that safety standards for motorcoach roofs be strengthened. Other motorcoach recommendations that have lingered on the board's "most wanted" list of safety recommendations include protections for occupants in rollovers and easy to open bus windows.

Teresa and Maurice Washington of Peoria, Ariz., who were sitting in the last row of bus, lost their 12-year-old son in the accident. The couple were also seriously injured.

"I'm still kicking myself for getting on a bus with no seatbelts," said Maurice Washington, 45, who attended Tuesday's hearing with his wife.

Legislation to toughen motorcoach safety standards -- including a requirement for seat belts -- died in Congress last year, but another bill has been introduced this year.

Board member Debbie Hersman said the bus crash was the third accident the board has reviewed in the past year in which the operator suffered from sleep apnea. She said the other two were a marine and an aviation accident.

(Copyright 2009 by The Associated Press. All Rights Reserved.)

Related topics