On Sunday the 6th of April 1969, a group of friends headed down to Mount Gambier to do some Pleasure diving after a late-night party. At 11 a.m., the ten-person group, which included three scuba divers, four snorkelers, and three non-diving buddies, arrived at the Kilsby sink hole. In the group were Bret and Patrick, who along with their friends George and Kerry had dived in the sink hole the day before and managed to go 55 meters deep before having to resurface.