TEMPE, Ariz. - The Tempe Police Department says a woman is dead after being hit by a Uber self-driving vehicle Sunday night. The woman is believed to be the first pedestrian killed by a self-driving vehicle in the U.S.

According to police, 49-year-old Elaine Herzberg attempted to cross Mill Avenue just south of Curry Road when she was struck. Police said she was not in a crosswalk.

Herzberg was taken to a hospital where she later died.

Police said the Uber vehicle was in autonomous mode with a vehicle operator in the front seat. The company confirmed this, adding there were no passengers in the back seat.

PHOTOS: Uber self-driving vehicle hits, kills woman in Tempe

Police said Uber is assisting in the investigation. The National Transportation Safety Board is also sending a team to investigate the crash.

In a statement, Tempe mayor Mark Mitchell said the crash was "tragic" and the community grieves for Herzberg.

Uber said it paused its self-driving operations across North America in the wake of the crash. Mitchell said he supported the decision.

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

Uber CEO Dara Khosrowshahi tweeted Monday that the company was "thinking of the victim's family."

Nearly a year ago, an Uber self-driving vehicle was involved in a different crash in Tempe when an Uber rolled onto its side. Nobody was injured in that crash, according to Tempe PD.