Police are searching for two men whose boat ran aground on Whitsunday Island in Queensland during the wild weather unleashed by Cyclone Debbie.
Difficult conditions following the cyclone are making the search difficult, The Courier Mail reports.
Mayor of Bowen, Whitsunday Andrew Wilcox said the aftermath of the cyclone looks "like a war zone".
A severe weather warning was issued for Queensland on Wednesday morning, forecasting heavy rain, strong winds and high tides.
Major river flooding is expected over the course of the week, the Queensland Bureau of Meterology reports.
Tropical Cyclone Debbie has been downgraded to a Category One storm, but it's still left a trail of damage across north-eastern Queensland.
It's moving slowly north towards Collinsville, leaving behind it wrecked buildings, infrastructure and 50,000 homes and businesses without power.
A Townsville is still trying to find her husband, who's in the Queensland town of Proserpine.
Jenny and David Clarke were speaking on the phone on Tuesday morning during the peak of the storm, when the roof came off the house.
"He called me to say the roof had come off and the ceiling caved in, one of the side doors was blown off and he pushed something heavy against it," she told the Courier Mail.
"I'm so worried ... I can't remember exactly but he said something like 'I'm not going to win this one'," she said.
Mrs Clarke, who is in hospital at Townsville, said she contacted emergency services but they were unable to help due to the dangerous conditions.
"I called the police at about 10:30am but there was nothing they could do because of the lockdown so I have no idea what has happened," she said.
Queenslanders woke on Wednesday to a giant clean-up mission after the "monster" storm.
Queensland Premier Annastacia Palaszczuk predicted "shock and awe" in the state.
Debbie was downgraded to a category one cyclone early on Wednesday, with winds easing from more than 200km/h down to 85km/h as the storm passed by Collinsville and headed inland.
The cyclone is expected to continue to weaken today, but heavy rain is expected to continue.
At its most ferocious the cyclone toppled trees, stripped buildings and left shorelines swamped after making landfall as a category four storm at midday yesterday near Airlie Beach.
Strong winds also lashed Airlie Beach, Proserpine and Bowen late in the afternoon.
The state's premier and police commissioner issued grave warnings to residents.
The premier, who on Monday warned it would be a "monster", said the state would be dealing with the impact of the "scary" cyclone for up to five days.
A man, believed to be aged in his 60s, was badly injured when a wall collapsed on him in Proserpine.
He is now in a stable condition in hospital.
"We are going to get lots of reports of damage and sadly I think we will also receive more reports of injuries, if not deaths. We need to be prepared for that," Commissioner Ian Stewart said on Tuesday afternoon.
The Australian Defence Force has mobilised soldiers, vehicles, aircraft and other resources to respond to Debbie, which the Insurance Council of Australia has already declared a "catastrophe".
The storm earlier pounded the Whitsunday Islands, with gusts of 263 km/h recorded at Hamilton Island while the jetty at Daydream Island was virtually washed away.
More than 48,000 homes were without power across the Bowen, Mackay and Whitsunday regions and more than 400 schools and childcare centres closed.
Agencies / Newshub.