Lassing mining disaster
Coordinates: 47°32′03″N 14°14′47″E / 47.534153°N 14.246306°E The mining disaster at Lassing occurred the morning of 17 July 1998. The accident in the Upper Styrian municipality of Lassing was the worst of its kind in Austria since 1945.
Lassing is the largest known carbonated talc deposit in the Eastern Alps. Geologically, it is part of the northern greywacke zone in Upper Styria. The deposit consists of two fields, the North and South Field, that latter having no connexion to the surface of the terrain. It is covered by unconsolidated rock, about 60 metres thick.
Lassing talc was discovered in 1891 by the local landowner, Krennmoar, during construction work. He secured the mining rights. In 1901, the firm of Bischetsrieder & Gielow began underground extraction. In the mid-1920s, mining was suspended for a few years due to the bankruptcy of the owner. In 1939, the mine was acquired by the family firm of Talkumwerke Naintsch. In 1988 the pit went into the possession of the Rio Tinto Group. In the 1990s, the mine and its associated processing works produced around 30,000 tonnes of talc per year. At the time of the accident the company had 34 employees of whom 8 worked underground.
Until the late 1970s, the North Field was worked by caving (Bruchbau). Then the mining operation moved to the South Field. Here, pillar and chamber work was used to extract the talc, using lean concrete. The South Field was opened up via the 204-metre-deep Renée Shaft, sunk in 1978-80. From the shaft, the talc deposit was accessed on ten levels.
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