Insufficient lubrication in the right-side tag axle wheel bearing assembly led to failed wheel bearings that eventually caused the ignition of the tire in the Texas bus tragedy that took 23 lives during Hurricane Rita evacuation efforts in September 2005, according to a report by the National Transportation Safety Board (NTSB).

It was also determined that the owner of the coach, Global Limo Inc., failed to conduct proper vehicle maintenance, do pre-trip inspections and complete post-trip drive vehicle inspection reports, which contributed to its inability to detect the insufficient wheel bearing lubrication.

The NTSB made several recommendations that included revising regulations to prohibit a commercial vehicle from operating with wheel seal or other hub lubrication leaks and developing detection systems to monitor wheelwell compartment temperatures.

NTSB officials also recommended further study of the causes of motorcoach and bus fires, as well as the development of new fire prevention and mitigation techniques. A synopsis of the report is available at www.ntsb.gov.