In 1976 a bus chartered to carry the Yuba City High School choir to a concert in a neighboring city drove off a ramp while exiting the freeway. The brakes failed due to lack of air pressure, with the inexperienced driver thought the low air pressure warning for the air brakes was a warning of low engine oil pressure. The bus fell 21.6 feet after striking the bridge rail. There were 52 passengers on the bus, and 29 of them were killed. All of the remaining passengers and the bus driver were critically injured.
Having been created in 1967, the NTSB investigated the crash and blamed the failure of a compressor drive belt supplying air to the brakes. The vehicle was old and the driver was inexperienced, and those were also contributing factors. The most important finding had to do with the curve of the ramp.
It took 20 years before it happened, but a memorial was built near the site and dedicated to the victims. The firefighters who had responded to the crash funded and built the memorial.
As a result of the crash, the freeway off-ramp was improved with a longer and flatter approach.