A 33-storey apartment high-rise near central Sydney was evacuated on Monday after residents reported hearing cracking noises.
More than 140 residents of the Opal Tower in Sydney's Olympic Park were forced from their homes along with occupants of nearby houses.
Train stations and roads near the building were closed while New South Wales state fire and rescue personnel assessed the structural integrity of the building. Firefighters set up tents around the building and directed pedestrians away.
New South Wales police said several residents left the building in the morning after hearing "cracking noises".
The tower was completed in August and has 392 flats, a retail area and a childcare centre.
Water and gas services were shut off and the tower was being isolated from the power grid, Fire and Rescue Acting Inspector Greg Wright said.
Meriton, the operator of the neighbouring building, said in an email to residents that there was "potential for the tower to collapse".
A resident of the Opal Tower told the Nine News network he heard a loud bang as if something in the building had "snapped".
Another resident told the Australian Broadcasting Corporation there were cracks on the building's 12th and 13th floors.
"I'm concerned, of course," he said. "A few days ago the doors looked different, like they couldn't close properly. And you do feel [movement] sometimes when there's strong wind."
Police are reported to have forced open the main doors to help residents leave.
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