A school bus was traveling down Occidental Road, near Stony Point Road in Santa Rosa on Thursday when a passenger from an oncoming car threw a bottle at it.
"And it hit the back of the mirror bracket right here, and it broke out the glass and the mirror," said Mike Rea, the executive director of the West County Transportation Agency.
This is the second attack on a school bus. Last week, another bottle shattered the windshield of a school bus while it was driving in the same area.
"The broken glass embedded in the driver's hand as well as in her eye," said Rea.
On Wednesday, three other cars were attacked along State Route 12, not far away. The CHP says a water bottle hammered a softball-sized hole in two windshields and shattered another. The drivers were sprayed with glass.
"A combined speed of 100 mph, the water bottle is going 50, oncoming traffic is going 50, so it makes quite an impact," said CHP Ofc. Jonathan Sloat.
It can turn a seemingly harmless bottle of water into a missile that can easily kill someone.
"We're looking for a white pickup truck, no camper shell, mid 2000's. That's all the information we have right now," said Sloat.
There were no students on either of the buses when they were attacked and so far no one has been seriously injured.
It's a misdemeanor in California to throw anything at a moving vehicle, but it becomes a felony as soon as someone gets hurt.
Anyone with information is asked to call the CHP at (707) 588-1400.
Bay City News contributed to this report.
