SYDNEY - Australia's army and emergency workers headed to areas of tropical Queensland state hardest hit by Cyclone Debbie on Wednesday, finding roads blocked by fallen trees, sugar cane fields flattened and widespread damage in coastal towns.

No deaths were reported after Debbie tore a trail of destruction through Australia's northeast on Tuesday as a Category 4 storm, one rung below the most dangerous wind speed level, before being gradually downgraded to a tropical low.

Thousands of people took shelter as tourist resorts along the world-famous Great Barrier Reef and coastal areas were belted with wind gusts stronger than 260 km/h. They woke to streets filled with debris.

"It's been absolutely smashed. You can't get out or in there's so many trees down," said Jon Clements, who was holidaying on Hamilton Island in the Whitsundays when the storm hit. "There are hardly any leaves left on any trees."

Queensland Premier Annastacia Palaszczuk said the worst-hit area was the Whitsunday coast and islands, some 900 kilometers northwest of the state capital, Brisbane. Water was cut to Daydream Island, where there were 200 guests and 100 staff, she said.

At Mackay, not far from the Whitsunday coast, fences and sheds were blown away, rivers were swollen and high tides and heavy swells still pounded the shore on Wednesday, Nine Network television footage showed.

Australian Prime Minister Malcolm Turnbull said at the Crisis Coordination Centre in Canberra: "Nature has flung her worst at the people of Queensland. There will be ... a lot of damage done now to recover, to clean up, to restore power, to make power lines safe."

More than 63,000 people were without electricity.

Queensland State Emergency Services Assistant Commissioner Peter Jeffrey said there had been "a limited amount of severe damage". Campbell Fuller, a spokesman for the Insurance Council of Australia, said it was too early to put a dollar figure on the damage.

A defense force flyover was scheduled for 9 am to assess the damage, Palaszczuk told reporters in Brisbane.

Heavy rain fell over a wide swath of Queensland on Wednesday as the system moved inland, with flood and poor weather warnings in place statewide.