It may have been wholly or partly the effect of ignition of coal dust, or what the manager called "unconsumed smoke," or both, by the strong draught of fire streaming up the steep roadway towards the level of the up-cast; or it may have been wholly or partly the effect of gas.

During the attempts to extinguish the fire the pair of doors already mentioned, which separated the in-take from the travelling dip in the return, were necessarily in frequent movement for the purpose of passing water through. If as was probably the case, the doors were occasionally open at the same time this would make a short cut for the air from the down-cast to the up-cast, and would momentarily stop or derange the ventilation throughout a great part of the mine.
Then so soon as the fire became strong towards the up-cast, it would greatly increases the draught and cause a large pull of air from all parts of the workings, and it would probably draw out whatever gas there may have been in the goafs or faces.
No great quantity of gas would be required to produce destructive effects in the immediate neighbourhood of the fire.

In the course of the inquiry it appeared that the manager had habitually been guilty of breaches of the general rules with respect to shots. It had been an ordinary practice to fire shots in the daytime with the ordinary shift of 200 to 300 men underground, at such places, and under such conditions with respect to gas, that the plain letter of the general rule was contravened.

The manager professed to believe that shots might lawfully be fired at any time unless gas was observable at the actual time of blasting. This improper practice was stopped in January by a notice from the Inspector of Mines.

At the inquiry on the 14th June, Mr. Whynne, HM Inspector, said; "When the manager of this colliery introduced the notion of having a forge in the pit, he ought to have taken extraordinary care himself that no danger could arise from it, as most likely no one else had ever seen a forge in a pit and would not see the danger that experienced persons would at once perceive; and I am bound to say, that had my attention been called to the matter, I would have protested against so dangerous an innovation, especially when the position of the forge was changed; for it was a very different thing when the first ten yards of the pipe passed through an atmosphere sometimes as low as 40 degrees, to what it would be when the air around the pipe would be nearly twice as warm.

In my opinion the pipe itself became foul with soot, which the sparks from the forge ignited; and as the pipes in the return air would be loaded outside with coal dust, the heat from the pipes would set the dust on fire, most likely at a point just through the door in the crosscut where there would be no current, and it may have been that the door was the first wood to take fire.

The opening and shutting of the doors on the main travelling brow would partially cause the air to pass directly from the down-cast pit to the up-cast, and thus cause a partial lull in the ventilation at the far end of the workings where gas was known to be produced, and when those doors were closed and the men ceased working, the whole of the air would take its usual course and bring the gas direct on to the fire.

When the manager left the pit the fire had already got beyond control, and considering the situation of the fire in the return air-way in the immediate neighbourhood of the up-cast in a fiery mine, it was as clear as anything can be made clear to an intelligent manager that an explosion was imminent, and a minute should not be lost in sending every man and boy out of the pit."

The coroner in his summing up to the jury said: I shall have to direct you to take into your consideration the fact that you are only sitting here to inquire into the death of three men, one of them being a man named Samuel Vickers, who at the time of the explosion was at the bottom of the shaft, and the other two being John Thompson, the manager's son and Henry Boulton, who were in the cage for the purpose of descending, at the time of the explosion. So that you will only have to consider the evidence so far as it bears upon the death of those three men.
It seems rather a curious arrangement that the other men having been killed, we are not able to take into consideration the cause of their death, but that is, as the law stands our duty, so that we shall have to abide by it.

He went on to explain the evidence of both Inspectors of Mines, that the ventilation at the pit was adequate.

But his next point was the furnace, and in this case there cannot be the slightest doubt that the explosion was occasioned by the heating of the flue from the smithy which set fire to the coal in the cross-cut and that in the spreading of the fire, from which some place or other gas was communicated to the fire and so caused the explosion.
During the excitement of trying to put out this fire the two ventilation doors, for a large proportion of the time were left open thus causing a short circuit of the ventilation, there by allowing gas to accumulate there. When it was found the men were unable to subdue the fire and closed the doors, normal ventilation was restored and the accumulated gas was then carried on to the fire and exploded, causing the deaths of the miners.

The coroner made two other points, first as to the question of the smithy. There is no doubt that in this district a smithy has never before been heard of at the bottom of a colliery. The Cockshead seam gives off a great quantity of gas, and anything that would give an unnecessary light of any description was a very bad thing to have at the bottom of the pit.

The other important question to be considered, relates to the steps that were taken by Mr. Thompson after the fire was out of control, to protect the lives of the workmen who were down the pit. One witness Mr. Atherton, said Mr. Thompson, the manager came up from the pit about 25 minutes before the explosion and was much exited, and said the mine is lost and the company ruined. He called Stubbs to arrange a scaffold to draw the horses out and Mr. Slater to prepare the stables. Others were told to make great haste and get out the horses as soon as they could.

Mr. Hollingshead, the prosecutor, said he intended to confine the evidence to the matters bearing upon the question whether or not Mr. Thompson, after he saw there was no hope of saving the pit, took the necessary precautions to save the men, which he ought to have taken.