The National Transportation Safety Board has determined that driver fatigue stemming from acute sleep loss was to blame in a multi-vehicle crash that claimed 10 lives in Oklahoma last year.

On June 26, 2009, a truck driven by Donald L. Creed, 76, of Willard, Mo., plowed into a line of stopped vehicles on I-44 about 90 miles east of Tulsa, killing 10 vehicle occupants and injuring six others, including himself.

Federal investigators say the driver was suffering from fatigue caused by circadian disruption associated with the driver's work schedule. The NTSB says Creed likely had less than five hours of sleep prior to beginning his work shift at 3 a.m. At the time of the crash, he had been on the road for more than 10 hours. Creed, who suffers from mild sleep apnea, failed to react to slowing and stopped traffic. He never applied brakes or performed any evasive maneuvers to avoid colliding with the traffic queue, the NTSB noted in its crash report, released Tuesday.

Among factors cited by NTSB as contributing to the severity of the crash are the truck's high impact speed and its structural incompatibility with passenger vehicles. It was traveling at 69 mph in a 75-mph area.

Investigators identified several major safety issues associated with this crash, and has issued recommendations intended to prevent future occurrences, and to improve future crash investigations.

Among them:

* The need for updated and comprehensive fatigue education materials and fatigue management programs;

* The need for a better understanding of the significance of heavy vehicle collision forces in crashes with smaller vehicles.

* Mandate the installation of electronic and video event recorders on commercial motor vehicles over 10,000 pounds and set performance standards for those devices.

The NTSB also reiterated previous recommendations to develop standards and require deployment of collision warning systems on new commercial vehicles, to require energy-absorbing under-ride protection for trucks, and to develop technologies to reduce fatigue-related accidents. In total, the NTSB issued nine new and six reiterated safety recommendations with this report.

Creed, who was not under the influence of alcohol or drugs at the time of the crash, has pleaded guilty to 10 counts of negligent homicide and was sentenced last month to 30 days in jail and 10 years' probation. He is barred from possessing a CDL as part of a plea agreement with prosecutors. He retired from the Kansas City-based Associated Wholesale Grocers shortly after the accident.

A synopsis of the accident investigation report, including the findings, probable cause, and safety recommendations, can be found on the Board Meetings page of the NTSB website. The complete report will be available on the website in several weeks.