On 26 October 1986 a land subsidence incident occurred at Haoud Berkaoui Oil Field in the northern part of the Algerian Sahara, which swallowed up the Okn-32 oil well and the core drill-2. The resulting crater was 80 m deep and 200 m in diameter. Six months later after subsequent subsidence events destroyed Okn-32 bis situated 80 m from Okn-32, the crater was 320 m in diameter. The origin of this event is discussed.