Rescuers on Tuesday rushed to reach residents trapped on their roofs overnight as the onslaught of muddy water tossed cars like toys, carried away furniture as it washed through stores. Scores of emergency calls were made as the flood swamped Toowoomba, a city of about 90,000 in Queensland state. At least two children were among the dead and Queensland police said the number of people missing had risen to 72.
"Right now we have every possible available resource deployed into this region to search for those people that we know are missing," Queensland Premier Anna Bligh told Australia's Nine Network. "This is going to be I think a very grim day."
Darkness and fog prohibited the state emergency service helicopters from overnight rescues, and some people were still waiting to be plucked off roofs Tuesday morning.
Rescue workers were battling more bad weather Tuesday. Heavy rain and thunderstorms were forecast for the region for most of the day, which could lead to more flash flooding, the Bureau of Meteorology warned.
Late Monday, Bligh told reporters a 26-foot wall of water was coursing through the low-lying communities from Toowoomba and eastward toward the state capital, Brisbane.
Officials urged residents of towns downstream from Toowoomba to immediately move to higher ground.
Bligh said about 30 people were isolated in a school in the town of Grantham, and 46 people had already been rescued by helicopters from rooftops in a number of towns.
Video taken in Toowoomba shows a man clutching a tree as the gushing water sweeps down a street, washing vehicles off the road.
"This is without a doubt our darkest hour of the last (two weeks)," Bligh told reporters.
The waters disappeared almost as fast as they arrived, leaving debris strewn throughout downtown Toowoomba and cars piled atop one another.
It was the latest drama for water-weary Queensland, which has been devastated by weeks of pounding rains and overflowing rivers. Eighteen people have died since late November and about 200,000 have been affected by the floods. Roads and rail lines have been cut, Queensland's coal industry has virtually shut down, and cattle ranching and farming across a large part of the state are at a standstill.
Queensland officials have said the price of rebuilding homes, businesses and infrastructure, coupled with economic losses, could be as high as $5 billion.
Some areas of Queensland have had more than 13 inches of rain in the past 24 hours, the Bureau of Meteorology said Monday.
Toowoomba resident Sarah Gordon said she saw at least 15 cars washed away.
"A lot of cars got swept down the road ... right down the creek," she said. "A few people were trapped, but they luckily got out."
Muddy waters also flowed through the main street in Gympie, one of more than 40 Queensland communities to be drenched by overflowing rivers. Gympie residents were frantically sandbagging buildings, but about a dozen businesses were inundated by Monday and dozens more were at risk as the Mary River burst its banks and kept rising.
The flooding in Gympie, home to 16,000 people, was not as bad as that elsewhere in recent weeks, when entire towns were submerged beneath an inland sea the size of France and Germany combined. But it was a sign the ground has little capacity left to soak up any more moisture, so any new rain is likely to make matters worse, officials said.
The water was 5 feet deep at Gympie's Royal Hotel.
"You want to cry," assistant manager Jess Philpot said. "It's going to go up to the roof."