Uber is abruptly pulling the plug on its self-driving cars after what appears to be an accident caused by human error, reports Bloomberg, which calls the development "the latest incident for a company reeling from multiple crises." An Uber vehicle wrecked in dramatic fashion, flipping on its side after another car failed to yield. "There was a person behind the wheel," says a Tempe police rep of the Uber car. "It is uncertain at this time if they were controlling the vehicle at the time of the collision." Uber is taking no chances, and is suspending its pilot programs in Arizona and Pittsburgh while it investigates: "We are continuing to look into this incident and can confirm we had no backseat passengers in the vehicle," says a rep. (More self-driving car stories.)