Restoration work was carried out by T.G. Jackson during the years 1905â€“1912, including the famous saving of the building from total collapse. Some waterlogged foundations on the south and east walls were reinforced by a diver, William Walker, packing the foundations with more than 25,000 bags of concrete, 115,000 concrete blocks, and 900,000 bricks. Walker worked six hours a day from 1906 to 1912 in total darkness at depths up to 6 metres (20 ft), and is credited with saving the cathedral from total collapse. For his troubles he was awarded the MVO.