By 1913, the North East Wales coal field was producing up to 3 million tonnes a year and employed over 10,000 people, dominating the economic and cultural life of the area. One of the worst mining disasters in British history occurred at Gresford Colliery in 1934 when underground explosions and a subsequent fire cost the lives of 266 men. However the industry went into decline after the First World War, and of the seven large-scale collieries operating in the Wrexham area in 1946, only two functional collieries remained by 1968. The last pit to close in the Borough was Bersham Colliery in 1986.The leatherworks in Pentrefelin and Tuttle Street, the many coal mines in the area, the brickworks in Abenbury, Brymbo Steelworks and the breweries all closed in the latter half of the 20th century. Wrexham suffered from the same problems as much of industrialised Britain and saw little investment in the 1970s.