Uber has removed its self-driving cars from the roads following what is believed to be the first fatality involving a fully autonomous car.

A self-driving Uber SUV struck and killed 49-year-old Elaine Herzberg as she walked her bicycle across a street in Tempe, Arizona, Sunday night, according to the Tempe police. The department is investigating the crash.

Rafael Vasquez, a 44-year-old test driver from Uber, was behind the wheel of the Volvo XC90 SUV at the time, the police said.

Based on preliminary information, the car was going approximately 40 mph in a 35 mph zone, according to Tempe Police Detective Lily Duran.

Police say the investigation does not at this time show significant signs of the SUV slowing before the crash. The Maricopa County Attorney's Office will determine whether charges will be filed.

"The vehicle involved is one of Uber's self-driving vehicles," the Tempe police said in a statement. "It was in autonomous mode at the time of the collision, with a vehicle operator behind the wheel."

Autonomous mode means the car is driving on its own. During tests, a person sits behind the wheel as a safeguard.

Uber is conducting tests of autonomous vehicles in Arizona, Pittsburgh, Toronto and other areas. Uber said it has stopped testing the vehicles throughout the United States and Canada.

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. https://t.co/cwTCVJjEuz — dara khosrowshahi (@dkhos) March 19, 2018

Uber said it is "fully cooperating" with local officials. "Our hearts go out to the victim's family," Uber said in a statement.

The National Transportation Safety Board said it is launching an investigation.

For self-driving cars, dealing with pedestrians and bicyclists is a challenging task. The self-driving industry has found quicker success with highway driving, which is a less complicated environment.

Uber has previously grounded its vehicles while investigating a crash. In 2017, Uber briefly pulled its vehicles from roads after an Uber self-driving vehicle in Tempe landed on its side.

Arizona is a hotbed of self-driving car development. Earlier this month, Arizona Governor Doug Ducey updated an executive order to allow self-driving cars to drive on state roads without a test driver behind the wheel.

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Meanwhile, Waymo, the self-driving arm of Google's parent company, is launching a public self-driving car service this year in the Phoenix, Arizona, area. Companies such as GM's Cruise and Intel are also testing in the state.

Arizona has little inclement weather. This makes it more appealing for self-driving cars, which can struggle in rain or during snowfall.

This isn't the first futuristic car involved in a fatal crash. In 2016, a man driving a Tesla was killed while its autopilot system was activated. But Tesla Autopilot is partially autonomous. A human driver is required to handle much of the driving.

However, Uber's system is designed to fully replace a human driver.