General Motors' driverless car unit Cruise said late Thursday it will suspend all operations nationwide after California regulators this week ordered the robotaxi operator to remove its driverless cars from state roads.
Tl;Dr The cars caused accidents by braking too hard and too quickly (because they sensed obstacles that weren't there), which caused people behind them to rear-end them. This apparently happened at least seven times and prompted a California government investigation, hence the voluntary nationwide suspension.