Uber has lost its autonomous driving permit in Arizona, after one of its self-driving cars struck and killed a woman in Tempe, Arizona last week.
Having welcomed the ride-hailing service to his state with open arms in 2016, Arizona Governor, Doug Ducey, used a letter to Uber CEO, Dara Khosrowshahi, to suspend its testing permit.
Ducey references video of the accident, telling the Uber CEO he found it "disturbing and alarming", and arguing it "raises many questions about the ability of Uber to continue testing in Arizona".
"As governor, my top priority is public safety," the letter says.
"Improving public safety has always been the emphasis of Arizona's approach to autonomous vehicle testing, and my expectation is that public safety is also the top priority for all who operate this technology in the state of Arizona.
"The incident that took place on March 18 is an unquestionable failure to comply with this expectation."
According to police in Tempe, Elaine Herzberg was killed after being struck by a self-driving Uber test vehicle operating in its autonomous mode.
The car was travelling at 40mph (64km/h) when it hit Herzberg, and there were no significant signs of it slowing down before the collision. The victim wasn't using a pedestrian crossing when she was killed. Dara Khosrowshahi described the incident as "incredibly sad news" on Twitter.
Footage released after the accident has since revealed the operator – essentially a human babysitter for the vehicle, there to take control if something goes wrong – was distracted in the lead up. Warning: the video doesn't show the moment of impact, but it may distress some viewers.
Uber has been testing self-driving cars in Arizona for just over 12 months, after the Californian Department of Motor Vehicles revoked its license for refusing to pay $150 for a testing permit in San Francisco.
The US National Transport Safety Board is investigating the collision, and Uber has suspended its self-driving program for the time being.