53 landslides causing 88 fatalities have been recorded since 1775 , notably the rockslide of 1889 .
Mitigation measures were implemented during the 20th century which reduced the number of incidents .
53 landslides causing 88 fatalities have been recorded since 1775 , notably the rockslide of 1889 , although mitigation measures were implemented during the 20th century which reduced the number of incidents .