Media playback is unsupported on your device

A look at safety inside N Yorkshire's Kellingley Colliery

20 August 2012 Last updated at 10:14 BST

The BBC has been given exclusive access to the UK's largest coal producer, Kellingley Colliery in North Yorkshire.

Two million tonnes of coal are cut at the "super-pit" every year - but its safety record has been questioned, with the deaths of three miners in the past four years.

Charlotte Leeming reports.