A barge loaded with thousands of litres of liquid sewage capsized off Sydney, trapping workers underwater, local media have reported.
Paramedics were able to rescue the workers from under the barge and bring them to the shore. One worker was hospitalised.
Investigators believe that the vessel could have capsized because it was overloaded or due to a technical malfunction.
The clean-up operation is currently underway and could take up to three days, specialists working at the scene told reporters.