By Phil Mercer
BBC News, Sydney
Huge seas have caused a coal freighter to run aground in wild storms off eastern Australia.
The Pasha Bulker is stuck on a sand bank
Environmentalists have said they fear that if the vessel broke up, it could spill its fuel, causing a maritime disaster.
Two other tankers have issued distress calls as giant waves threaten to drag them towards the coast near the port city of Newcastle.
The ships have been pounded by gale force winds and waves up to 17m (55ft).
One bulk carrier, the Pasha Bulker, is in real trouble. It was pushed onto a sand bank off Newcastle where it had been waiting its turn to head to port to collect a consignment of coal.
Plans for tugs to pull the ship out to sea were abandoned because of the rough conditions.
With the 40,000-tonne vessel stranded so precariously in shallow waters, a risky mission was launched to rescue the crew.
Police helicopters were called in as the storm continued to bear down on the coast.
Twenty-one crewmen, all thought to be from the Philippines, were winched to safety and were reported to be in good health.
The drama, though, is far from over.
The authorities are worried that the freighter could break up and leak huge amounts of oil and diesel into the ocean. Witnesses have said traces of fuel have begun washing up on the beach.
Two other bulk carriers off Newcastle have issued distress calls but maritime officials have said their anchors are "still holding".
Weather conditions in the area north of Sydney are expected to get worse in the coming hours.