Uber halts autonomous vehicle program in Toranto after woman stuck by a car.

An Uber self-driving car hit and killed a woman crossing the street in Arizona, police said on Monday, marking the first fatality caused by an autonomous vehicle and a potential blow to the technology expected to transform transportation.

The ride services company said it was suspending North American tests of its self-driving vehicles, which are currently going on in Arizona, Pittsburgh and Toronto.

So-called robot cars, when fully developed by companies including Uber, Alphabet Inc and General Motors Co, are expected to drastically cut down on motor vehicle fatalities and create billion-dollar businesses. But Monday’s accident underscored the possible challenges ahead for the promising technology as the cars confront real-world situations involving real people.