SYDNEY -- More than 3,000 people living in or near a 36-story apartment high-rise at Sydney's Olympic Park were evacuated Monday after residents reported hearing cracking noises.
Firefighters and engineers were expected to enter the Opal Tower complex late Monday to examine what caused the reported cracks on its 10th floor and to determine whether the building is in danger of collapse.
"It's not going to be done in minutes. Hopefully it won't take longer than hours," Fire and Rescue Acting Inspector Greg Wright told reporters.
Experts using sensitive monitoring equipment determined the $165 million building, completed in August, had moved between 1 and 2 millimeters, according to police Detective Superintendent Philip Rogerson.
Police reportedly had to use heavy equipment to force open doors to allow residents to escape. An exclusion zone with a radius of 1 kilometer (half a mile) was established around the building, forcing the evacuation of neighboring buildings and the closure of roads and a train station.
New South Wales police said in a statement that the alarm was raised by residents who reported hearing "cracking noises" throughout the morning.
The tower, which looms over the central site of the 2000 Sydney Olympics, has 392 apartments, a retail area and a childcare center.
Water and gas services were shut off and the tower was being isolated from the power grid, Wright said.
Meriton, the operator of the neighboring 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."
Residents from Opal Tower and surrounding properties had been taken to an evacuation center and it was not clearly if or when they would be able to return to their homes.
This story has been edited to correct the building's height to 36 stories.