As bad as the 1901 disaster had been it was to be overshadowed by the biggest mining disaster in Great Britain, which occurred at this colliery on Tuesday 14th of October 1913, killing 439 miners.
It was 8 o'clock in the morning with a workforce of 950 men underground when there was a massive explosion, the force of which sent the cage in the Lancaster pit rocketing up the shaft and crashing into the pithead gear. The force of the blast smashed the wooden platform on which the banksman John Mogridge was standing; he was decapitated by a large splinter of timber.
There had been little damage to York pit, so the manager and some other men slowly descended this shaft. When they reached about 530 yards down some girders blocking their progress halted their descent, but by shouting down the shaft to the nine-foot level they were heartened by the replies that some of the men were safe.