A self-driving car has hit and killed a woman in the southwestern United States in what is believed to be the first fatal pedestrian crash involving the new technology. Police said Monday a self-driving sport utility vehicle owned by the ride sharing company, Uber, struck a woman walking outside of a crosswalk in the Phoenix suburb of Tempe. They say the episode happened overnight Sunday to Monday and say the woman later died from her injuries in a hospital. Uber said it had suspended its autonomous vehicle program across the United States and Canada following the accident. Police say the vehicle was in autonomous mode, but had an operator behind the wheel, when the accident took place. Testing of self-driving cars by various companies has been going on for months in the Phoenix area, as well as Pittsburgh, San Francisco and Toronto as automakers and technology companies compete to be the first to introduce the new technology. The U.S. National Highway Traffic Safety Administration and National Transportation Safety Board said they are sending a team to gather information about the crash. Uber CEO Dara Khosrowshahi expressed condolences on Twitter and said the company is working with local law enforcement on the investigation. The fatal crash will most likely raise questions about regulations for self-driving cars. Arizona has offered little regulations for the new technology, which has led to many technology companies flocking to the state to test their autonomous vehicles. Proponents of the new technology argue that self-driving cars will prove to be safer than human drivers, because the cars will not get distracted and will obey all traffic laws. However, critics have expressed concerns about the safety of the technology, including the ability of the autonomous technology to deal with unpredictable events.