Apparently the six people who died from poisonous gas at Hetton Colliery in Kelloe were a rescue party: "Kelloe pit, two miles away, was connected underground to Trimdon Grange, and undermanager Herman C Shler took a rescue party in that way. They saw the extraordinary force of the blast had blown doors open, and then they succumbed to the afterdamp - poisonous gases created by the explosion. Five would-be rescuers, including 73-year-old Mr Shler, died at Kelloe."