California Highway Patrol officers are seeking additional information on a crash that left a bus overturned and more than a dozen people injured last week. 

The bus, which operates for Kern County Transit, suddenly veered off of Sierra Highway near West Avenue C at around 11:15 a.m. on Wednesday, ending up overturned near railroad tracks, according to a news release from the CHP. 

Officers say that the bus, which had as many as 30 people aboard, was heading northbound on Sierra Highway when something struck the windshield.

"After reviewing the available footage, we did confirm an object struck the bus's windshield and then the driver," said a statement from CHP Officer Jordon Church. "The investigation is ongoing, and while we are reviewing all available evidence, it's unclear whether we'll be able to determine exactly what the object was that struck the driver."

In all, the crash left 15 people hospitalized with injuries ranging from minor to severe. Three people, a mother and her two children, had to be airlifted to a nearby hospital, police said at the time. 

Police also said that the driver lost consciousness after she was struck by the object. They believe the injuries she suffered in the crash could be life-altering.

This isn't the first time that a driver was struck by an object while driving in the area in the last year.

On Oct. 8, 2024, a woman was killed when a rock flew threw her windshield and struck her while she drove along SR-138 near SR-18 in the Antelope Valley. A passenger in the car told police that the rock "was thrown from an unknown location," said a CHP statement from the time. 

The deadly incident came just two days after another driver reported a similar occurrence in the same area. They told police that their windshield was also shattered by a rock, though there were no injuries in that instance. 

Police have not indicated that there is any connection between any of the incidents. 

Anyone who knows more is asked to contact CHP at (661) 743-6060 or (323) 259-3200.