LONDON — An enormous ash cloud from a remote Icelandic volcano caused the biggest flight disruption since the Sept. 11, 2001, terrorist attacks Thursday as it drifted over northern Europe and stranded travelers on six continents. Officials said it could take days for the skies to become safe again in one of aviation's most congested areas.
The volcano beneath the Eyjafjallajokull (ay-yah-FYAH'-plah-yer-kuh-duhl) glacier began erupting Wednesday for the second time in less than a month, shooting smoke and steam miles into the air.
The cloud, floating 20,000 feet to 36,000 feet above Earth and capable of knocking out jet engines, wrecked travel plans for tens of thousands of people who couldn't see the source of their frustration — except indirectly, when the ash created vivid red and lavender sunsets.
Video showed spectacular images of hot gases melting the thick ice, sending cascades of water thundering down the steep slopes of the volcano.
The ash cloud became a menace to air travel as it drifted south and east toward northern Europe — including Britain, about 1,200 miles away.
Nonemergency flights in Britain were canceled, and most will stay grounded until at least midday today. Authorities in Ireland, Denmark, Norway, Sweden, Finland and Belgium also closed their air space. France shut down 24 airports, including the main hub of Charles de Gaulle in Paris. Germany's Berlin and Hamburg airports were shut Thursday evening, and several flights out of the United States had to double back.
Kyla Evans, spokeswoman for air traffic service Eurocontrol, said the ash had led to the cancellation of about 4,000 flights within Europe on Thursday, and that could rise to 6,000 today.
Several U.S. flights bound for London's Heathrow Airport, including those from Chicago, San Francisco, Denver, Las Vegas and New York, had to return to their departure cities or land elsewhere when London airports were closed. Canadian airlines also canceled some Europe-bound flights.
In Washington, the Federal Aviation Administration said it was working with airlines to try to reroute some flights around the huge ash cloud, which is hundreds of miles wide. Flights from Asia, Africa, South America, Australia and the Middle East to Heathrow and other top European hubs were also put on hold.
At Heathrow, normally one of the world's busiest airports with more than 1,200 flights and 180,000 travelers a day, passengers stared forlornly at departure boards on which every flight was listed as canceled.
"We made it all the way to takeoff on the plane. … They even showed us the safety video," said Sarah Davis, 29, a physiotherapist from Portsmouth in southern England who was hoping to fly to Los Angeles. "I'm upset. I only get so much vacation."
Ironically, among the immense disruptions, Iceland's Keflavik airport remained open Thursday.
About 700 people from rural areas near the volcano were evacuated Thursday because of flash flooding, as water carrying icebergs the size of small houses rushed down the mountain. Most evacuees were allowed to return home after the floods subsided, but more flash floods are expected as long as the volcano keeps erupting, said Rognvaldur Olafsson of the Civil Protection Department.