Officials say a man has been killed by floodwaters that have inundated parts of Australia's third-largest city.

Queensland state Premier Anna Bligh says the 24-year-old man was killed in Brisbane on Thursday, the first to die in the city. That brings to 24 the total number of people killed since driving rain and floods began in Queensland in late November.

The Brisbane River reached its crest early Thursday, swamping thousands of homes and businesses with water.

Bligh says the clean-up effort will reach "postwar proportions."