TEMPE, Ariz. – Officials said an Arizona woman was killed after being struck by a self-driving Uber vehicle early Monday. The incident is believed to be the first of its kind.

As a result of the accident in the Phoenix suburb of Tempe, the company suspended all testing of self-driving vehicles in cities across the country.

Tempe Police Sgt. Ronald Elcock told Fox News that Elaine Herzberg, 49, was walking outside of a crosswalk when she was struck by the computer operated automobile.

“The vehicle was traveling northbound just south of Curry Rd. when a female walking outside of the crosswalk crossed the road from west to east when she was struck by the Uber vehicle,” police said.

Herzberg was taken to a nearby hospital, but she passed away a short time later, according to police.

Although there was an operator behind the wheel at the time of the collision, the self-driving Uber was in autonomous mode, police said.

Uber said on Twitter the company is fully cooperating with local authorities as the investigation occurs, and told Fox News it has halted testing of the self-driving vehicles in cities across the country.

“Our hearts go out to the victim’s family,” Uber Comms tweeted. “We’re fully cooperating with @TempePolice and local authorities as they investigate this incident.”

Uber CEO Dara Khosrowshahi tweeted: “Some incredibly sad news out of Arizona. We’re thinking of the victim’s family as we work with local law enforcement to understand what happened.”

The company has been testing autonomous vehicles in Pittsburgh, San Francisco, Toronto and the greater Phoenix area for months. Automakers and tech companies are competing to be first with the technology.

The National Transportation Safety Board said it was sending a team to investigate the crash.

The National Highway Traffic Safety Administration said in a statement to Reuters it is “in contact with Uber, Volvo, federal, state and local authorities regarding the incident,” and will take appropriate action.

The federal government has voluntary guidelines for companies that want to test autonomous vehicles. Consequently, this leaves much of the regulation up to individual states.

The U.S. Department of Transportation is considering other voluntary guidelines that it says will help foster innovation. But Transportation Secretary Elaine Chaos also has said technology and automobile companies need to allay public fears of self-driving vehicles, citing a poll showing that 78 percent of people fear riding in autonomous vehicles.

Moreover, the number of states considering legislation related to autonomous vehicles gradually has increased each year, according to the National Conference of State Legislatures. In 2017 alone, 33 states introduced legislation.

California is among those that require manufacturers to report any incidents to the Department of Motor Vehicles during the autonomous vehicle testing phase. As of early March, the agency received 59 such reports.

The mayor of Tempe has been a vocal cheerleader for Uber Technologies Inc.’s efforts to use his streets as a test track for robot rides, reported bloombergquint.com.

“Uber is really operating very safely on our roadways,” Mark Mitchell, who was elected mayor in May 2012, said in a Feb. 14 phone interview. “We’re enforcing the traffic laws for everyone, whether it’s autonomous or regular, law-abiding citizens.”

In an emailed statement Monday, Mitchell called the accident tragic. Yet he also urged against drawing “conclusions prematurely” as the Tempe Police completes its investigation.

“When a bicyclist, pedestrian or motorist is killed, it should be an opportunity for Tempe to pause and think about what can be done to make our roadways even safer,” he said.

“All indications we have had in the past show that traffic laws are being obeyed by the companies testing here,” Mitchell added. “Our city leadership and Tempe Police will pursue any and all answers to what happened in order to ensure safety moving forward.”