Women and very young children (they had to be aged 10 or above) were not employed in the pit and, according to E. Raper (Social and Working Conditions in the village of New Hartley 1845–1900), this gave a higher standard of life for the miners: "the miner in New Hartley would return home after a hard day's work to a warm, clean, comfortable home and usually a substantial hot meal".

An explosion at the St Hilda pit in South Shields in 1839[6] had led (as the result of a public meeting)[7] to the formation of a committee to consider the prevention of accidents in mines.

The Shields Committee issued their report in 1843; it had found that mines in the North-East were unnecessarily at risk of explosions because they were generally inadequately ventilated with too few shafts for the size of the underground workings (a view supported by evidence from George Stephenson, amongst others).

The committee's report had specifically argued against the practice for all new works (which it thought Parliament should legislate against), of sinking a single shaft and sub-dividing it by bratticing to separate in- and out-flowing ventilation air (since any explosion destroying the bratticing would destroy the ventilation of the mine and ensure the death by asphyxiation of those underground).

[9] A powerful steam engine, 'the largest in the county employed in mining purpose',[10] was therefore installed in 1855 to operate pumps to recover the pit.

In the meantime, a staple was provided within which was a ladder; this allowed escape to the yard seam from the low main should there be a major inrush of water ("the only thing that was feared").

Realising that the man was exhausted, having just come off shift, the under-viewer Joseph Humble[k] sent him home to rest whilst the main rescue effort was organised.

[l] The initial rescue attempt was carried out under the direction of Humble, Carr (owner and viewer), G B Hunter (Cowpen & North Seaton), Hugh Taylor (Backworth) and Matthias Dunn (HM Inspector of Mines).

Friday the rescuers had removed the debris in the shaft (mostly timber from the brattice) to within about 5 fathoms (30 ft; 9.1 m) from the furnace drift, and thought they could hear noises from the men in the yard seam.

[o] William Coulson, the master sinker who had supervised the sinking of the shaft in 1845–46, was on a train passing through Hartley station on his way to another job.

[4] On offering his services, he was put in charge late on Friday afternoon, the previous committee yielding to his greater experience.

On Wednesday morning, with the bratticing incomplete, George Emmerson (one of Coulson's sinkers sent to investigate if what remained of the pumps would collapse further if debris around them was removed)[4] got three yards into the furnace drift before being forced back by the gas.

Two pitmen in their number (William Adams of Cowpen and Robert Wilson of Backworth) were invited to go down the pit and report back to their colleagues on how things stood;[u] exceeding their instructions, they managed to enter the yard seam and found dead men.

[4] Humble and a fellow-viewer (a Mr Hall from Trimdon) penetrated further and found all the miners dead, but on their return to the bank were severely affected by the gas.

[21] Although the rescuers had thought they had heard signalling from the trapped men as late as Saturday night,[21] the last entry in the notebook of the back overman described a prayer meeting held at 1.45 on Friday afternoon.

[4] The task was now recovery of bodies, and, the check-viewer told the waiters at the pit-head, it was no good throwing away the lives of living men to obtain the bodies of dead men: further entries into the yard seam were suspended until the canvas bratticing was completed, and the shaft properly timbered and cleared further to allow the yard seam to be accessed directly, rather than via the furnace drift.

[22] The following day, the Journal reported ugly scenes at the pithead, with demands that the bodies be retrieved immediately; conversely, the workers in the shaft were becoming more reluctant to run the risk of the continuing rockfalls.

In the event, the corpses were raised to the pit head to be identified as far as possible by the tally-boy, sprinkled with chloride of lime, shrouded, and coffined.

[25] The Journal reporter described the consequent appearance of the village: All the blinds were drawn; but, looking in at the open doors, we saw coffins in every house.

And so we passed up the row, and saw two, and three, and four coffins all in one little room, till, at last, coming to the end house, we were appalled to see a perfect pile of them…; and looking round, we were informed that seven dead bodies lay in the cottage.

In every house women were sitting by the fire nursing their grief; and strong men, pale and dejected, were visibly suffering from the reaction of the excitement of the past week.

[27] Fifty men were employed in digging the graves, and they did not complete their task until well after interments started (at about one thirty); dusk was falling as the last coffin was buried.

[28] An inquest was held on Tuesday 21 January 1862 on the five men killed directly by the beam fall, but this heard little evidence, the coroner expecting a "more particular inquiry, should some of the rest not be got out alive".

Sir George Grey, the Home Secretary (to whom the Mining Inspectorate reported) sent down an expert ((John) Kenyon Blackwell) to assist the coroner.

[4] Hosking did not think a pump piston had wedged, the bottom spear had broken under normal load: "The wood does not appear to me to have been of very good quality.

"[4] He dismissed as irrelevant two points which had attracted comment:[z] Blackwell's report to Grey (written a week after the inquest) concurred with Hosking and drew attention to factors which Blackwell felt had made the accident more likely than for most pumping engines; Told that all hope was lost, Queen Victoria (who was herself in mourning, having lost her husband, Prince Albert, only a month previously) sent a telegram of condolence, following it up by a letter: "Her Majesty commands me to say that her tenderest sympathy is with the widows and mothers and that her own misery only makes her feel the more for them".

[ac] The British public responded generously; despite attempts to persuade them to give instead to other worthwhile causes, £20,000 was raised in London alone;[37] the total receipts of the Hartley Relief Fund came to £83,000.

[38] A fuller reckoning of dependents including 26 posthumous children brought their number up to 467,[39] but even on the most pessimistic assumptions, only £55,000 was needed to provide for them, so in 1863 £20,000 was distributed between the districts covered by each mining inspector, to be administered by local committees and applied for the relief of suffering caused by colliery accidents.

The Hartley Relief Fund was wound up in 1909; after buying annuities for the ten surviving dependents £13,000 was left and went to the Northumberland and Durham Aged Miners' Homes Associations; the accommodation built with the money was to bear a suitable inscription.

The inquest verdict was returned on 6 February 1862 and was 'accidental death' with riders including: The jury cannot close this painful inquiry without expressing their strong opinion of the imperative necessity that all working collieries should have at least a second shaft or outlet, to afford the workmen the means of escape should any obstruction take place, as occurred at the New Hartley Pit; and that in future the beams of colliery engines should be made of malleable metal.