Millions of Australians were wiping a film of reddish Outback grit from nearly everything Thursday after the country's worst dust storm in seven decades played havoc with transport systems and sent asthmatics scurrying inside.

The country's largest airport said normal flight schedules were resuming Thursday, a day after the dust cloud caused almost 20 international flights to be diverted away from Sydney and threw domestic schedules into turmoil.

Skies over eastern Australia were mostly clear and blue, and New South Wales state health officials said they expected air pollution to drop to normal safe levels after reaching record highs the day before. But child care centers in Sydney kept young children inside Thursday until an official all-clear came through.

The dust storm Wednesday had shrouded Sydney and surrounding areas for about eight hours, blotting out landmarks such as the Sydney Opera House and Harbour Bridge and even reaching underground to coat subway stations.

The haze, churned by powerful winds that lifted thousands of tons of topsoil from the arid and drought-stricken inland, was visible from space, appearing as a huge brown smudge in satellite photographs of Australia.

The Sydney Morning Herald called it "the day the country blew into town."

No one was hurt in the storm, though health officials responded to hundreds of calls in two states from people complaining of breathing difficulties.

One man had a lucky escape when his four-wheel drive vehicle overturned on a remote Outback road. John White set off an emergency beacon and waited for about 2 1/2 hours for police to arrive as the wind slowly covered the vehicle with sand, Senior Constable Neale McShane of Birdsville police told the Australian Broadcasting Corp.

"I spent most of the day pushing dirt out so I didn't get buried myself," White told Sky News television.

As it cleared away from Sydney on Wednesday afternoon, the dust moved north along the heavily populated eastern coastal area clogging skies over the Queensland state capital of Brisbane. The city enjoyed clear blue skies on Thursday, though the dust cloud continued to push farther north into remote parts of the state.

Emergency services responded to hundreds of calls about tree branches brought down by strong winds.

"The dust was quite spectacular, but didn't in itself cause a lot of damage," state Emergency Service Minister Steve Whan said.

But Mark Goodsell of the Australian Industry Group said the dust storm will end up costing New South Wales state tens of millions of dollars in lost productivity from interruptions Wednesday in flights and construction.

The storm also ripped an unknown amount of topsoil from farms across a huge swath of Australia.

"That's the real story of yesterday, what kind of damage is being done permanently to the rural landscape," Goodsell told the ABC.

The dust so thoroughly blanketed everything in its path — clothes, cars, train seats — that New South Wales and Queensland government promised to lift water restrictions, imposed because of the drought, so residents could clean their homes and vehicles.

Airlines on Thursday were still trying to get back on schedule, after diverted and canceled flights sent a ripple of delays and congestion through airports in Sydney, Brisbane and the southern city of Melbourne.