Ash clouds from Iceland’s spewing volcano halted air traffic across Europe as authorities closed air spaces over Britain, Ireland and the Nordic countries.
Tens of thousands of passengers were stranded in one of most disruptive events to hit air travel in years.
Authorities said it was not even clear when it would be safe enough to fly again. In one sobering prediction, a scientist in Iceland said the ejection of volcanic ash — and therefore the disruptions in air travel — could continue for days or even weeks.
Britain’s Civil Aviation Authority said non-emergency flights would be banned in all airports until at least 6 p.m. (1700 GMT, 1 p.m. EDT). Irish authorities also closed their air space for at least eight hours, as did aviation authorities in Denmark, Norway, Sweden and Finland.
The move shut down London’s five major airports including Heathrow, a major trans-Atlantic hub that handles upwards of 1,200 flights and 180,000 passengers per day. Shutdowns and cancellations spread to France, Belgium, the Netherlands, Denmark, Ireland, Sweden, Finland and Switzerland.