Analysis of information sources in references of the Wikipedia article "Kambalda Nickel Operations" in English language version.
On 14 November 1978 it was found that a gauge measuring pulp density in the Kambalda Mill [...] could not be located. The gauge [...] contained a small amount of radioactive caesium 137.
The Western Mining Corporation has increased security at its Dambalda mine to prevent any more radioactive devices being lost.