During the night of 20-21 October the peak of tip 7 subsided by 9--10 feet (2.7--3 m); the spoil movement was discovered at 7.30am by the first members of the morning shift manning the heaps.
During the night of 20-21 October the peak of tip 7 subsided by 9--10 feet (2.7--3 m) and the rails on which the spoil was transported to the top of the tip had fallen into the hole. The spoil movement was discovered at 7.30am by the first members of the morning shift manning the heaps.