but by 1910 the population had soared to 160,000. The Rhondda had become the heart of a massive South Wales coal industry. Mining accidents below ground were common, and in 1896 fifty-seven men and boys were killed in a gas explosion at the Tylorstown Colliery. An enquiry found that the pit involved had not been properly inspected over the previous 15 months. Ebbw Vale, the valley of the Ebbw River which stretches from the town of Ebbw Vale to Newport, includes the mining towns and villages of Newbridge, Risca, Crumlin, Abercarn and Cwmcarn. The Carboniferous Black Vein coal seams in the area lay some 900 feet (275 metres) below the surface and the mining activity associated with it was responsible for many tragic subsurface explosions, roof collapses and mining accidents. Now the Valleys' heavy industrial past is overprinted with urban regeneration, tourism and multi-national investment. Large factory units, either empty or turned over to retail use, bear witness to the lack of success in replacing older industries. Language The native language of the majority of people in South Wales is English, but there are many who also speak Welsh. In western parts of Glamorgan, particularly the Neath and Swansea Valleys, there remain significant Welsh-speaking communities such as Ystradgynlais and Ystalyfera, which share a heritage with other ex-anthracite mining areas in eastern Carmarthenshire, as much as with the Glamorgan valleys. The local slang, dialect and phrases of the South Wales Valleys communities have been referred to as 'Wenglish', and are often used with comic effect. The dialect is found in such coastal towns as Barry, as featured in the BBC comedy series, Gavin & Stacey. Welsh is now a compulsory language up to GCSE level for all students who start their education in Wales. Several secondary schools offering Welsh medium education operate in this area, for example Ysgol Gyfun Llanhari in Pontyclun, Ysgol Gyfun Y Cymmer in Porth in the Rhondda, Ysgol Gyfun Rhydywaun in Penywaun in the Cynon Valley, Ysgol Gyfun Gwynllyw in Pontypool, Ysgol Gyfun Cwm Rhymni in Blackwood, Ysgol Gymraeg Plasmawr in Cardiff and Ysgol Gyfun Garth Olwg in Church Village. A significant number of people from ethnic minority communities speak another language as their first language, particularly in Cardiff and Newport. Commonly spoken languages in some areas include Punjabi, Bengali, Arabic, Somali and Chinese, and increasingly Central European languages such as Polish. In the 19th and early