One of Google's 23 self-driving Lexus SUVs was rear-ended in recent weeks at an intersection in Mountain View, and three employees who were in the car at the time suffered minor whiplash. The Associated Press picked up the story via Google employee Chris Urmson, who wrote about the July 1 crash on Medium.

California law requires someone to be behind the wheel of an autonomous vehicle on the road, and there were two other passengers in the car at the time.

Though Google's self-driving cars, which have been officially in testing on Silicon Valley streets for two months now, have been involved in minor accidents before, this is the first time any injuries have been reported. Urmson previously said that the vehicles had been involved in 11 minor accidents since 2009 — and that was back in May — and since then there have been three more, including this one on July 1. In all cases, other vehicles were the cause of the collisions, 11 of which were rear-enders, and you can read all about them here, and they've all been reported to the DMV.

Urmson shared the video below which shows a real-time animation of the cars on the road at the time, and illustrating how the Google vehicle braked normally along with two cars in front of it, and the car that hit them did not brake at all. It was traveling at 17 mph when the collision occurred.

Google is currently driving 23 of the SUVs as well as two of these prototype smart-car things on the streets of Mountain View.

And though Google's reports make it sound like getting rear-ended in Mountain View is a constant danger, Urmson says that their testing is pointing to the fact that such crashes are likely happening everywhere at a higher rate than what is reported, and this project will allow them "to make some assumptions about that real crashes-per-miles-driven rate." What they want to prove, ultimately, is that robots ought to be doing all of our driving for us, because humans are terrible and clumsy.

Previously: Google Is Developing Its Own Uber For Driverless Cars