A gasoline (petrol) tank at an oil storage and distribution terminal was overfilled with gasoline (petrol) which subsequently overflowed into a bund. A large vapour cloud formed and eventually flowed over the bund wall. Multiple explosions occurred and the resulting major fire engulfed 20 large storage tanks. Large clouds of black smoke from the burning fuel spread over southern England and beyond. The fire burned for 5 days, destroying most of the terminal and damaging surrounding homes and business premises. Fortunately, there were no fatalities (probably because the explosion took place in the early hours of a Sunday morning when very few people were on site). However, 43 people suffered minor injuries and approximately 2000 people had to be evacuated from the area. Firewater, foam and fuel product runoff from the site caused pollution of an underlying potable water aquifer.

Basic Cause:
Loss of primary containment (LOPC) due to failure of the servo-type level sensor used by the automatic tank gauging system and the digital high level switch used by the automatic high level shutdown system.