At 11.03 pm on 28 May 1993, a seismic event was detected in a remote region of Western Australia. It measured 3.6 on the Richter scale.

After the 1995 Tokyo gas attack, Australian investigators conducted inquiries in the region, which Aum Shinrikyo was known to be active in. Aum Shinrikyo, a Japanese doomsday sect with a known nuclear research program, bought the sheep ranch property at Banjawarn Station, near the epicenter, in September 1993. This property was also the site of a Uranium deposit. Aum used a front company to import electrical equipment including transformers, static converters, generators, coaxial cabling, batteries, meters and tools and protective equipment into Australia in September 1993. Aum proceeded to mine Uranium.

According to some reports, Aum Shinrikyo employed disgruntled Russian nuclear scientists and made inquiries about purchasing nuclear warheads from Russians. They also attempted to refine uranium at the facility.

What actually happened in May 1993 is still unclear. However, it is known that three operatives from Aum were in the region.
factgirl: I'm with you on this. I did not intend to make it seem like the site was a former uranium mine. Australia has huge amounts of uranium, though: it is the #2 producer worldwide, after Canada. I've seen references to uranium ore in that region being of low grade. It's hard to find reliable data on the web. Some UFO researchers (how is that for credibility?) think the AUM were attracted to the region because UFO fans described a fireball at the seismic event (probably a meteor).