The National Transportation Safety Board released a preliminary report for its ongoing investigation of the Dec. 17 crash involving a SUV and 14-passenger coach bus in South Carolina.

A 2015 Chevrolet Equinox sport utility vehicle driven by a 53-year-old driver, was traveling east on US Highway 76 in Belton, South Carolina, when it entered an approximately three-degree righthand curve, departed the eastbound travel lane, and crossed into the westbound lane, colliding with the front left corner a 2009 Ford E350 14-passenger medium-size bus. The bus, carrying seven passengers, was operated by the Anderson County Disabilities and Special Needs Board with a 27‑year‑old driver.

The preliminary report states the driver of the SUV had been swerving completely across both lanes from shoulder to shoulder before striking the bus. According to data from the SUV’s airbag control module, the driver was not wearing a seat belt. She was ejected from the SUV and fatally injured during the crash sequence.

All occupants of the bus wore restraints. However, as a result of the crash, one lap-belted passenger seated behind the driver was partially ejected and fatally injured. The bus driver and the six remaining passengers sustained minor to serious injuries.

While the investigation continues to determine probable cause, the crash does demonstrate why Strengthen Occupant Protection remains on the NTSB 2019-2020 Most Wanted List of Transportation Safety Improvements, according to the agency.

The information contained in the report is preliminary and subject to change. As such, no conclusions regarding probable cause or contributing factors should be made from the information in the preliminary report. The crash remains under investigation and analysis of the crash facts, along with conclusions and a determination of probable cause, will come at a later date when the final report is completed.

The NTSB is conducting its safety investigation alongside the South Carolina Highway Patrol, which is conducting a separate, parallel investigation. To view the preliminary report, click here.