Undiagnosed sleep apnea a factor in deadly California bus crash

A federal safety board has determined that undiagnosed sleep apnea was a factor in a deadly bus crash in California last year, becoming just the latest fatal incident to be linked to the sleeping disorder.

The National Transportation Safety Board (NTSB) said Tuesday that undetected sleep apnea, along with a poor alert system for stopped highway traffic near utility work, was to blame for a crash that occurred when a tour bus slammed into the back of a tractor-trailer near Palm Springs, Calif., last October.

The incident left 13 people dead and 31 others injured.

Investigators determined that the truck driver, who had been stopped on the highway in traffic due to utility work, did not resume driving after the traffic stoppage because he most likely fell asleep at the wheel due to fatigue from his “undiagnosed, moderate-to-severe obstructive sleep apnea.”

The truck driver was found to have violated hours-of-service rules for several days prior to the crash, while the bus driver was also likely fatigued and had untreated diabetes, according to investigators. Neither vehicle was equipped with crash avoidance technology.

Even though the truck driver was severely obese and considered to be at very high risk for having obstructive sleep apnea, he had not been tested for the condition. Sleep apnea causes a person’s airways to close and stops their breathing during sleep, potentially leading to daytime drowsiness.

The disorder has been linked to a number of deadly transportation incidents, including a fatal New Jersey Transit train crash last year.

The Obama administration had announced plans to require transportation companies to screen their rail, train and bus operators for sleep apnea.

But the Trump administration decided to abandon the screening proposal this summer, saying there was not enough evidence to support rulemaking and pointing out that a number of companies already voluntarily test their employees for sleep apnea.

“Federal and state regulators, commercial motor carriers and professional drivers can do better,” said NTSB Chairman Robert Sumwalt. “Given the stakes, they must do better.’’

The NTSB said that while the Federal Motor Carrier Safety Administration (FMCSA) has issued guidance on sleep apnea screening, the agency has not disseminated the guidance to the medical examiners that perform commercial driver’s license medical examinations.

The board, which issued a total of eight safety recommendations, urged FMCSA to develop a program that identifies commercial drivers who are at the highest risk for sleep apnea and require those drivers to be appropriately evaluated and effectively treated, if necessary.