An Adelaide woman who was cleaning her fish tank overnight said she and her two children became ill when a piece of coral fell into the water and caused a chemical reaction.
Emergency crews were called to the home in the city's south at 2am when gases were released into the air.
The family was rushed to hospital, where they are now recovering.
Firefighters have cordoned off the property and the street has been closed as they wait for specialists chemical experts to arrive to determine what sort of gases are in the air.
