[1] Shortly after midday on 11 September 1878, with 325 men and boys working underground, a large explosion ripped through the Prince of Wales Colliery.

The colliery’s steam whistle blew, signalling that an emergency was underway, drawing colliers and the families of those trapped to the pit head.

Several fires ignited the coal seams and supporting timber structures, filling the mine with smoke.

A rescue team entered the main shaft but damage meant the winding gear could reach only 295 yards (270 m) down.

Two miles (3 km) from the main pit, another rescue team ventured into a shallow downcast or ventilation shaft, but were ordered to withdraw due to the likelihood of another explosion happening.