It was bound to happen sooner or later.

A self-driving car reportedly struck and killed a pedestrian in Arizona Sunday, in what is believed to be the first-ever death involving an autonomous vehicle.

The car was owned an operated by Uber as part of a test of the new technology that is being rolled out in various cities across the country. Google, Waymo, Audi, and other companies have been exploring driverless car technology, slowly introducing autonomous cars—often with human backup drivers in the front seat—to real roadways.

There has been guarded enthusiasm for autonomous cars among tech enthusiasts and even many local governments, who view the technology as a potential solution to traffic accidents and deaths. A death involving a driverless car could change that conversation a bit.

Of course, developers and proponents of autonomous vehicles have never said the new driving technology will reduce traffic-related deaths to zero. Rather, they take the broad view that an autonomous system will make travel safer than if humans were behind the wheel. noted that an average of 16 pedestrians are killed by piloted vehicles every day in America. There were 37,461 people killed in motor vehicle accidents last year.

“This tragedy will no doubt stoke fears about putting our lives in the hands of car computers,” Vox said. “So let’s not forget that getting into, or walking or biking near, a car piloted by a human is one of the most dangerous activities we can do every day.”

In the District of Columbia, officials have made eliminating traffic deaths a priority with its DC Vision Zero initiative. The city noted that there have been 107,000 crashes over the last five years, with 118 fatalities. Reducing traffic deaths has piqued the city’s interest in autonomous cars; earlier this year it issued a request for information to explore a pilot program of driverless cars near L’Enfant Plaza.

Montgomery County last year also aimed to eliminate traffic deaths with its own Vision Zero plan, which calls for an elimination of traffic deaths by 2030. The plan does not address the arrival of autonomous vehicles specifically, but notes that most traffic accidents are the result of human error and alludes to the need for technological advancements.

“Human error is inevitable; the transportation system should be designed to anticipate error so the consequences are not severe injury or death,” Montgomery County’s Vision Zero plan said. “Advancements in vehicle design and technology, roadway engineering, personal electronic devices, etc., are necessary components for avoiding the impacts of human errors.”

Does a death involving a driverless car change your opinion of autonomous vehicles?

Click here to sign up for commuter news and real-time traffic updates for free, delivered to your inbox Mondays, Wednesdays and Fridays.