The
Hartley Colliery disaster (also known as the
Hartley Pit disaster or
Hester Pit disaster) was a coal
mining accident in
Northumberland, England that occurred on Thursday 16 January 1862 and resulted in the deaths of 204 men. The beam of the pit's pumping engine broke and fell down the shaft, trapping the men below. The disaster prompted a change in UK law that henceforth required all collieries to have at least two independent means of escape.