China moved first. Indonesia followed. Then Singapore and Australia.
By midday Wednesday more than 30 countries and airlines from India to Italy had banned Boeing 737 Max jets from their skies after a second fatal crash of one of the planes brought the death toll to 346 people. The deadly crashes raised concerns around the world that they may have both been caused by software Boeing added to the modern version of its workhorse jet.
But the U.S. aviation regulator repeatedly stood by the American-made plane, even as close allies like the European Union decided to suspend the plane from operating there.
It left the Federal Aviation Administration, which has presided over an unprecedented period of commercial airline safety at home, in an unfamiliar state: alone.