There are several thousand loose fill slopes in Hong Kong. These have generally been in place for many years and usually predate the establishment of the Geotechnical Control Office in 1977. They were placed to form platforms for roads and other purposes and are now situated within the infrastructure of Hong Kong. There have been a few major failures of loose fill slopes and the Sau Mau Ping disasters in 1972 and 1976 showed the devastation that failure of a loose fill slope could cause. In both cases the failures were sudden with the failed material moving rapidly downhill in a semi-liquid-like state. There have been examples of similar rapid failures of slopes in natural material (e.g. the 1995 Fei Tsui Road landslide) but loose fill is observed to be more mobile and move further when it fails posing greater threat to life.