Several investigations are being held into the cause of the derailment of a freight train in the Northern Territory on Tuesday.
Floodwaters swept part of the train into the Edith River and cut the Stuart Highway north of the Top End town of Katherine. The train was carrying copper concentrate.
The ABC reports the derailment has prompted questions over the safety of transporting toxic substances, including uranium, during bad weather there.
Northern Territory Environment Department head Jim Grant says the copper concentrate has been ''washed all over the place''.
NT Environment Centre director Stuart Blanch says the investigations need to establish why the train was allowed to cross the river while it was flooded.
The railway from Alice Springs to Darwin is owned by Genesee and Wyoming Australia.
Managing director Bert Easthope says the track was tested before the train crossed the bridge.
Chief Minister Paul Henderson says the Australian Transport Safety Bureau is also investigating.