Concerns are being raised after a woman was killed by one of Uber’s self-driving cars in Tempe, AZ on Sunday night. This was the first fatal crash in the U.S. involving a such a vehicle.

The victim of the accident, Elaine Herzburg, was 49 years old, and was crossing outside of a crosswalk with a bicycle. An operator was in the self-driving vehicle, but she was unable to intervene in time. The car was traveling at about 40 mph when it struck Herzberg.

Uber issued a statement saying:

Our hearts go out to the victim’s family. We are fully cooperating with local authorities in their investigation of this incident.

This incident isn’t the first accident that Uber has encountered with their self-driving vehicles. Last year, there was a crash involving one of its Volvo SUVs, which also occurred in Arizona.

The accident has raised questions about current self-driving car experiments. Uber temporarily suspended their self-driving car operations in Phoenix, Pittsburgh, San Francisco and Toronto. Some are also calling for stronger regulations on the vehicles to prevent similar accidents in the future, while others are questioning the wisdom of continuing to pursue the technology if it cannot accurately identify and avoid a human being.

What do you think? Should there be tighter restrictions on self-driving vehicles?