During the night of 28th February—1st March, a fall some 20 yards long occurred on the east side of the dip development face. The next morning an inspection of the face was made by Mr. Haslam, the under-manager, whilst air measurements were made by Mr. K. Middleton, ventilation officer. It was found that the quantity of air passing on the left face had been reduced slightly from the measurement of the previous week, and in view of the possibility of the face becoming blocked still further, the under-manager decided to avoid a reduction in the quantity flowing in the district by raising the screens fastened on two wooden frames in the connection between Nos. 1 and 2 intakes some 20 yards back from, and parallel with, the face. The openings in both the frames had areas of 18 square feet (see inset B, Plate I).

Until 5th March the Plodder district was supervised by one deputy on each shift; however, the growth of the district, in particular the need for the flank face to be started as soon as possible, made it desirable for additional supervision to be provided, so on 6th March (the day of the explosion) an extra deputy, J. E. Houghton, was appointed for the day shift. He took charge of the dip development face, the two intakes and the Haigh Yard level, whilst H. Dickenson, who had formerly taken charge of the whole of the Plodder, concentrated his attention on the opening up of the new flank face which was to advance towards Gibfield. No other changes of note nor events of an unusual nature took place until the early part of the shift when the explosion occurred.

On the morning of the day of the explosion, eight men were employed on the east side of the dip development face, preparing to take a coal buttock past the fall. The deputy in charge, the newly-appointed J. E. Houghton, found no gas when testing at the face rippings and in the general body of the air. The two brattice sheets in the connection between the two intakes were in the raised position but only a slight current of air was passing; similarly, only a small amount of air was flowing past the fall on the face.

Houghton made his pre-shift inspection from 1 to 2 p.m. No one had been working at the Pikrose haulage situated at the high point of No. 2 intake during his shift and, though Houghton visited this place, he did not make a test for gas there. After telephoning a satisfactory report on the condition of the district to the pit bottom, Houghton returned to the coal face to supervise the moving of a coal cutting machine, remaining there for about an hour.

The afternoon shift was admitted by deputy V. Robinson. Five men, P. Socha, J. Howcroft, E. Nutter, T. Dzundza and W. Beckett, were sent to work at the ripping, ten yards up No. 2 drift, where enlarging for the air crossing was being carried out. Normally only three men worked there but the place where Dzundza and Beckett were usually employed was not available on that shift. Other men whom Robinson passed in were two bricklayers, E. Williams and R. Sutton, who were to work on the Haigh Yard level; F. Woodward, who was to operate the Pikrose haulage at the top of No. 2 drift which was to be used by the five rippers to lower the dirt they were to fill the short distance down the drift; and some pit bottom and general oncost workers. Since the haulage which Woodward was to operate was situated more than 300 feet from the nearest coal face, it was not a requirement of the Coal and Other Mines (Ventilation) Regulations, 1956, that a firedamp detector should be provided there.

Several sets of men who had started work at 10 o'clock in the morning had not completed their shift when the afternoon men arrived.

Whilst on his way to the pit bottom after finishing work at the face, Houghton met Robinson at the foot of No. 2 intake. Together these officials examined the ripping lip where Socha and his men were to work and found no gas to be present; they parted company at the foot of the drift, Houghton making his way to the pit bottom. Robinson stated that he then went up No. 2 drift to the Pikrose hauler, since Woodward was to work there during his shift, made several tests for gas and found the place clear. Woodward was not there. Robinson came down the drift and went inbye along the Haigh Yard level, taking a look at the men employed there. Whilst he was near the foot of No. 1 drift he was called to the telephone, and about 3.30 p.m. was speaking to Houghton concerning a routine matter when Woodward came up and said that he wanted the electricians because of a fault which he had found on the Pikrose panel — when he put the switch in there was a buzzing noise and a smell of burning. Houghton, in the pit bottom. overheard this conversation but told Robinson that Woodward had already telephoned to him to this effect from the telephone 30 yards outbye the foot of No. 2 drift and added that he had just examined the lamps of two electricians, L. Inman and K. Tryner. who had descended the shaft for a routine examination, and that he had informed them of Woodward's message. As there was some doubt as to the cause of the trouble in the panel, two mechanics, W. Pearson and T. Morris, who happened to be in the pit bottom at the time, also decided to go to the Pikrose, though in fact they paid a short visit to a haulage on the Haigh Yard level before following the electricians and Woodward up No. 2.

Robinson then went inbye up No. 1 drift and Houghton went out of the mine.

Just before 4 o'clock F. Wolstenholme, an oncost man working near No. 1 pit bottom, felt a strong blast of air which appeared to come from the direction of the Plodder district; the blast was followed almost at once by a cloud of dust. Wolstenholme went inbye and encountered the five men who had been working near the foot of No. 2 drift (Socha, Howcroft, Nutter, Dzundza and Beckett) and one of the bricklayers, E. Williams, all badly burned, making their way to the pit bottom. A little further on he met the second bricklayer, R. Sutton who was guiding a badly burned man, the mechanic W. Pearson. At the time the fumes were too thick for Wolstenholme to go in any further than the top of St. George's clip brow, so he got on the telephone and informed the undermanager, Mr. Haslam, that something serious had happened in the Plodder district and that help was needed at once. Later Wolstenholme managed to get in as far as the foot of No. 2 intake, where he found some timber, clothing and brattice cloth on fire. This material he attacked with extinguishers. Other workers from the pit bottom joined Wolstenholme and some time afterwards, a body of men came from the direction of No. 1 intake in the charge of deputy Robinson. Most of this party went out to the pit bottom but a few stayed to help to deal with the burning material until the arrival of the under-manager a little later.

R. Sutton, bricklayer, was working 15 to 20 yards outbye of the foot of No. 1 intake when the explosion occurred. He was blown over and was burned slightly on the right cheek and forehead but was able to make his way outbye through the dust and smoke. Just as he was passing the foot of No. 2 intake he heard cries for help and turned to find W. Pearson, one of the mechanics, badly burned, groping his way out. Sutton took charge of Pearson and led him out to the pit bottom, where they met the rest of the burnt men.

A number of oncost men had been working at the foot of No. 1 intake. They were blown over and enveloped in dust when the blast occurred. However, one of them, R. Littler, managed to ring up the surface saying that he thought an explosion had occurred between there and the pit bottom. After a short examination of the Haigh Yard level had been made and a lot of smoke had been encountered, it was decided to go inbye up No. 1 intake, with a view to escaping via Gibfield colliery, as it was feared that there was a fire on the Chanters side. At the junction of No. 1 intake and the crosscuts the party met the men from the dip face under H. Ashton and soon afterwards were joined by deputy Robinson and the workmen from the flank face. After a telephone conversation had been held with the manager on the surface, the 21 men formed a "crocodile" and on the manager's advice set off back to Chanters pit bottom via No. 1 intake. The atmosphere was thick with smoke and dust until the foot of No. 2 drift was reached where, in a somewhat clearer atmosphere, they came across the men who were dealing with the burning material.

Deputy Robinson had just charged two holes in the roof ripping in Gibfield Stret when he felt the rush of air created by the explosion. He thought a three-inch compressed air pipe had broken so proceeded to fire the shots, simultaneously. However, the dust became thicker and from a nearby leak it was evident that the air range was still full of compressed air, so Robinson got all his men to make their way to the junction of the connecting road and No. 1 intake. H. Ashton and his body of men were there, as previously described, and after the conversation with the manager on the telephone the party of 21 made their way safely down No. 1 intake and along the Haigh Yard level to the foot of No. 2 intake.

Soon afterwards, Mr. Haslam, under-manager, arrived from the surface. At the time it was understood that only Woodward was missing. It was thought possible that he might have escaped towards the face on the inbye side of his haulage so Mr. Haslam and deputy Houghton, who also had come back down the pit to help, went up No. 1 intake, along the connection and back up No. 2 intake for about 20 yards. They could get no further on account of the smoke and fumes and, not encountering Woodward, returned to the outbye end of No. 2; there they found that unsuccessful attempts, foiled by smoke, had been made to go up No. 2 and also that Mr. Hiller, the manager, and a rescue team had just arrived.

Whilst Mr. Haslam was in the district he opened the two doors between No. 1 intake and the return in order to try to short circuit some of the smoke into the return.

It was realised about now that other men besides Woodward were missing. A rescue team, wearing self-contained breathing apparatus, went up No. 2 intake and located one body, that of L. Inman, electrician. Further visits were made up the drift and by 6.40 p.m. four bodies had been brought down, that of T. Morris, mechanic, being difficult to find since it was lying in that part of the road behind the brick wall where the conveyor had originally run, a part not normally used for travelling. Inman's body was five yards inbye of the Pikrose panel and those of Tryner and Woodward were some five yards farther inbye (see Plate IV).

A rescue team then made an inspection of No. 2 intake right to the face and confirmed that there was no residual fire. The air in No. 2 remained stagnant until the manager had a sheet erected on the Haigh Yard level between the two intakes. Soon after the sheet had been set it was possible to go up No. 2 intake; gas was present at the top of the drift opposite the Pikrose, in a layer three feet thick below the top of the arch girders at a percentage sufficient to extinguish a safety lamp.

Further inspection of the district by rescue men confirmed that there were no fires anywhere. An examination of the electrical gear associated with the Pikrose haulage showed that the isolating switch was in the "off" position and that the front cover of the main chamber had been taken off and was lying on the floor. Three of the four pins securing the cover of the busbar chamber had been removed, whilst the fourth was slack; the cover itself had been twisted through an angle of about 25 degrees (see Plate II (a)). A brief inspection showed that the twisted top cover and one of the busbars were in contact and that at the point of contact signs of electrical fusion were present. All persons were then withdrawn and the district was fenced off until the following morning.