With police in Tempe, Ariz., pointing to a pedestrian’s behavior and possible visibility issues as factors in a deadly driverless Uber crash, federal investigators on Tuesday continued to scour digital and other evidence looking for broader safety insights for the burgeoning industry.

Tempe police Sgt. Ronald Elcock said video from Uber’s autonomous 2017 Volvo shows the 49-year-old victim “approaching the vehicle” late Sunday night. He warned residents of this city of 175,000 of the dangers of crossing “mid-block.”

“As soon as she walked into a lane of traffic, she was struck by the vehicle,” Elcock said. “Using the crosswalks will definitely limit any tragic incidents from happening again.”

The crash prompted Uber to abruptly halt testing of its autonomous vehicles in Tempe — and across North America. The moratorium on testing includes San Francisco, Phoenix, Pittsburgh and Toronto.

Tempe’s latest pedestrian fatality — officials say more than 60 people have been killed on city streets over the past six years — became the first known death involving a driverless vehicle, thrusting the community into a national debate about the proper level of state and federal oversight.

Scores of companies are vying for competitive advantage in the wide-open and potentially transformative world of autonomous vehicles, with technology developers touting the safety benefits of removing fallible human beings from the driver’s seat — and critics warning that many iterations of the enabling technologies are being implemented before they are ready.

The National Highway Traffic Safety Administration, which administers voluntary federal guidelines on the deployment of driverless cars, said it sent a “special crash investigation” team to Tempe as part of its “vigilant oversight and authority over the safety of all motor vehicles and equipment, including automated technologies.” The agency said it was in contact with Uber and Volvo, as well as local, state and federal authorities.

But critics continued to argue that the vehicles are being unleashed without adequate standards and oversight.

“These cars are being rushed onto the public highways way before they’re ready,” said Joan Claybrook, a consumer advocate and former head of NHTSA under President Jimmy Carter. “The public are the guinea pigs for these early vehicles.”

The National Transportation Safety Board, an independent body that does painstaking and precise investigations into everything from bridge collapses to train wrecks and plane crashes, continued to gather information in Arizona on Tuesday, including pulling from electronic data sources stored in the vehicle or sent to Uber.

The safety body said its investigation would examine the operating condition of the SUV, the backup driver’s interactions with it and “opportunities for the vehicle or driver to detect” the pedestrian. On Tuesday, investigators began to examine the Volvo XC90 and the accident site, and viewed video footage of the crash from a dashboard-mounted camera, the NTSB said. Investigators also gathered information on the vehicle technology, the pedestrian and the driver, according to the NTSB.

“The NTSB investigates select highway crashes that can advance knowledge of broad or new safety issues,” the panel said. Spokesman Eric Weiss added that depending on the findings, the investigation could lead to broader recommendations encompassing entities other than Uber.

But it’s still early, Weiss said.

“We would look at the probable cause of this accident, and then if there are any other broader implications, we would look at that as well,” Weiss said.

But while the team is expected to remain in Tempe for the rest of the week, it was not expected to release the probable cause of the crash or other related findings until the investigation is complete.

Uber said it continues to cooperate with authorities in their probe of the crash. Because of the ongoing investigation, the company declined to comment on the state of the investigation or answer questions related to it.

Tech companies and automakers have billed driverless cars as a tool to reduce the nation’s toll of 40,000 road fatalities a year. The robo-cars — enabled by sophisticated sensors and algorithms — have a more complete view of their surroundings than human drivers, advocates argue. And they can avoid making all-too-human mistakes, backers say.

“What would prevent those [fatalities] would be not speeding, not drinking, not texting, not being distracted,” said Bryant Walker Smith, a law professor at the University of South Carolina. “The hope is that automated driving, when it is ready, will be able to address many of those causes without introducing significant new sources of crashes.”

Smith also said that pedestrians and bicyclists often get blamed in these cases “because the pedestrians are the dead ones, and they’re not there to defend themselves.”

“Really, any crash with that pedestrian should have been avoidable, unless the circumstances were really strange, meaning: Physics won. If the victim was visible and the path of the victim was reasonably predictable, then she should not have been hit,” Smith said.

Police investigators believe that the woman who was killed, Elaine Herzberg, had been near a median packed with trees and shrubs in the run-up to the crash, and it is unclear what the car or its backup driver might have been able to see before she was hit.

“It’s different when you’re seeing it through your own eyes as opposed to trying to see it through a camera sometimes,” said Tempe police Cmdr. Jeffrey Glover, adding that reconstructions will be done to help answer that question as part of the investigation.

Uber’s self-driving cars rely on a combination of cameras, GPS sensors and laser-powered components to get a sense of their surroundings, according to a diagram provided by the company.

Among the most critical components is a top-mounted lidar unit, which uses lasers to scan the environment and provide a 360-degree view of the car’s surroundings.

The cars also include seven cameras. A forward-facing lens looks out for factors such as braking vehicles, pedestrians in the road, and traffic lights and signage; side and rear cameras provide a more comprehensive view. A roof-mounted GPS antenna records the position of the vehicle. The car also includes computers and data storage components that allow the cars to continually process data they collect, according to Uber.

Elcock said the Volvo XC90 was traveling at about 40 mph when it struck Herzberg, who had been pushing a bicycle.

The Uber’s backup driver, identified by Elcock as Rafaela Vasquez, 44, was cooperative and showed no signs of impairment, according to police.

The police investigation “did not show at this time that there were significant signs of the vehicle slowing down,” Elcock said, but the investigation is ongoing.