LSD was evidently in limited recreational use in Australia in the early 1960s, but is believed to have been initially restricted to those with connections to the scientific and the medical communities. LSD overdose was suggested as a possible cause of the January 2, 1962 deaths of CSIRO scientists Gilbert Bogle and his lover, Margaret Chandler, but is very unlikely as there are no known cases of a LSD fatal overdose and other more likely causes of death have been suggested. Large quantities of LSD began to appear in Australia around 1968, and soon permeated the music scene and youth culture in general, especially in the capital cities. The major source of supply during this period is believed to have been American servicemen visiting Australia (mainly Sydney) from Vietnam on "rest and recreation" (R&R) leave, although the growing connections between American and Australian organized crime in the late 1960s may also have facilitated its importation. Recreational LSD use among young people was on a par with that in other countries in Australia by the early 1970s and continued until late in the decade. LSD is not believed to have been manufactured locally in a significant quantity (if at all) and most if not all supplies were sourced from overseas.