Uber has suspended all road testing of fully autonomous vehicles following the tragic death of a pedestrian in Arizona. On Sunday night, a woman walking in a crosswalk in Tempe was struck by an Uber Volvo. There was a human in the Volvo, however, the vehicle was in self-driving mode at the time of the accident. The 49-year-old woman, identified as Elaine Herzberg, passed away at the hospital. The incident happened near Mill Avenue and Curry Road.

Although self-driving vehicles are often considered to be safer than human-operated cars, these type of vehicles are still in the testing phases. As a result of the accident, Uber has suspended all testing in Phoenix, San Francisco, Toronto, and Pittsburgh. Uber and its competitors are in a battle to be the first company to perfect this type of technology.

The National Transportation Safety Board is sending a team of investigators to the scene of the accident to fully investigate the incident. Although this accident is widely believed to be the first episode involving a pedestrian, Tesla came under scrutiny in May of 2016 when one of its self-driving vehicles was involved in an accident that killed the car’s driver. Although proponents of self-driving vehicles boast that the technology can make roads safer by eliminating human error, many government officials are skeptical of these claims. In the year 2017, 33 states introduced legislation designed to regulate these fully autonomous vehicles. The state of California is the most strict, requiring that any incidents involving self-driving cars be reported to motor vehicle department authorities for review and recording.