It was caused when a busy signalman, Alfred Sutton, forgot about a pair of light engines waiting at his down (northbound) starting signal to return to their shed at Carlisle.

Hawes Junction station was approximately 3.5 miles (5.6 km) south of Ais Gill summit, the highest point on the steeply graded Settle and Carlisle line.

448 and 548, under drivers Edwin Scott and George William Bath) had been turned and coupled together, and were waiting on the "lie-bye" road alongside the down (northbound, away from London) line.

[10] Driver Bath had been injured in the leg but made his way on foot to the Ais Gill signal box a mile and a half north to summon help.

The signalman there, Benjamin Bellas, sent another light engine under driver John William Judd, with Bath, along the up line.

The engine crews and the express train's guards, the sleeping car attendants, some platelayers from a hut a short distance up the line and a shepherd whose home was nearby tried desperately to rescue the trapped passengers but were eventually driven back by thick smoke.

[13] The immediate cause of the accident was that signalman Sutton forgot that he had moved the two light engines to the down line, waiting there to proceed to Carlisle.

Sutton refused to believe him until he had checked his train register, and then telephoned signalman Bellas at Aisgill to ask whether the two light engines had gone through.

[18][19] He naturally judged that Sutton's admitted mistake was the primary cause of the accident, but made a number of observations on the conduct of others and several recommendations.

[20][21] Pringle considered that drivers Scott and Bath were also at fault for failing to carry out the requirements of Rule 55, which was created to remind signalmen in this situation.

The large number of light engine movements would naturally increase the total amount of traffic at Hawes Junction, but Pringle's report specifically rejected the assertion that overwork was a factor.

The high level of traffic movements made Hawes Junction a prime location for the use of reminder appliances.

The Board of Trade accident report unequivocally recommended this, and the Midland Railway rapidly complied both here and at 900 other locations on their network.

[24] Since the outbreak of the fire and its intensity was undoubtedly caused by escaping gas from the Pintsch lighting system, the report recommended measures such as automatic shut-off valves and safer placement of cylinders.

[25] However, Pringle recommended that electricity be adopted as the universal method for lighting coaches, although he allowed that it would take many years for such a change to take effect fully.