Residents of south-east Australia received a shock on Wednesday morning as an earthquake rippled through Melbourne and regional Victoria, reaching as a far as Canberra, Adelaide and parts of New South Wales.
People quickly flocked to social media in the aftermath, reporting violent shaking which knocked things from walls and shelves and forced evacuations in Melbourne's CBD.
Here's what we know so far.
Where did the earthquake hit?
At around 9:15am on Wednesday a magnitude-5.9 earthquake was detected in the Alpine National Park near Mansfield in Victoria's north-east.
Geoscience Australia said the quake originated at a depth of 10 kilometres. It was originally reported as a magnitude-6 quake, but was downgraded shortly after.
It was felt heavily 190 kilometres away in Melbourne, as well as in Sydney, Canberra, Adelaide, and Launceston in Tasmania.
Victoria State Emergency Service has confirmed there is no tsunami threat following the quake.
Reports suggested the tremors lasted about 20 seconds in Melbourne, and up to a minute closer to the epicentre.
"It shook here in the northern suburbs of Melbourne for about 15-20 seconds so it's quite a significant earthquake," Seismology Research Centre head Adam Pascale said.
Video from the ABC studio in Melbourne showed the building shaking.
The quake is potentially the largest one recorded in eastern Australia since European settlement, according to Geoscience Australia.
Victoria's State Emergency Service had received about 26,000 reports from people who had felt the quake as of 10:30am.
A second magnitude-4.1 earthquake was recorded in the vicinity of the first about 15 minutes later at a depth of 12km.
In the time between those, a third quake measuring magnitude-3.5 was recorded at a depth of 6km.
Landslides have also been recorded in the state's north-east alpine region.
There have been no reports of serious injuries
There have so far been no reports of serious injuries or fatalities as a result of the quake.
Speaking from the United States on Wednesday morning Prime Minister Scott Morrison said the event was "very disturbing" but there were no reports of fatalities.
The federal government was standing by to support Victorians as required, he said, after communicating with Premier Daniel Andrews over text.
Following the tremors, Mr Andrews tweeted: "Yes, that was an earthquake."
He urged Victorians to go to the Emergency Victoria website for the latest information.
Buildings in Melbourne have been damaged
There have been reports of damage throughout Melbourne, with photos showing a partially collapsed building on Chapel Street in the inner city.
Photos and videos of the street show bricks and debris strewn across the street, after the top floor of Betty's Burgers in Prahran partially collapsed.
Apartment buildings in inner Melbourne have also been evacuated and parts of the city have experienced power outages.
A spokesperson from Victoria's State Emergency Service said there had been reports of damage to several buildings in the Mansfield area, near the epicentre, including to the local ambulance centre.
Mansfield resident Karen McGregor said windows on the FoodWorks grocery store had buckled but there was no significant damage to the building.
"The windows started shaking, the walls, and everything on the desk, it was really quite scary," she said.
Expect aftershocks
Experts have warned Victorians to prepare for aftershocks, which could continue for months.
"There is a small likelihood that there could be a larger event but we'll see as we go," Mr Pascale said.
Emergency Victoria has urged residents to expect aftershocks, stay away from damaged buildings and avoid driving unless absolutely necessary.
If people are out and about they urged people to "stay safe and use common sense".
But while hundreds of aftershocks could be expected, many won't be felt by humans.
