Electricity is gradually being restored to Darwin after a power failure lasting more than 10 hours that caused the closure of schools, public transport and the public service.
The Northern Territory government called the blackout an emergency and said there would be an inquiry into how it happened. Beginning at 1am it brought much of the city to a standstill.
Power was also lost at Katherine and Pine Creek.
The territory's Power and Water Corporation says the "code black" was caused by a tripped circuit at Hudson Creek sub-station at Berrimah, in the city's east.
Power and water minister Dave Tollner called on people to stay calm and safe on the roads, where all traffic lights were out.
There have been no delays reported at Darwin airport, which is running on generator power.
Power and Water Corporation spokesperson Jim Bamber says the cause of the fault will be investigated once power is fully restored.