"Clarity of planning and careful execution" allowed Cadent gas engineers to cut off three gas mains near to Grenfell Tower at the height of the emergency, helping to bring the fire under control after gas sustained the fire in its later phases, the official inquiry has found.
These were the words of inquiry chair Sir Martin Moore-Bick in his phase one Grenfell Tower Inquiry report, published on 30 October, which also clarified that gas played little role in the fire's outbreak or early stages.
The gas was eventually cut off at 23.40 on 15 June as flames continued to rage. Removing the fuel source had an instant effect, assisting the fire brigade to bring it under control, the report said.
Chapter 31 describes in detail how a team of Cadent gas engineers worked throughout 15 June to cut off the gassupply, by excavating the three gas pipes and closing them off with a "bagging" technique.
The report concludes: "There can be no doubt that the Cadent team did an excellent job in finding the local gas mains and cutting off the supply of gas to the tower. They succeeded in completing a challenging task over a long period of time in difficult and sometimes dangerous conditions."
While gas was found not to have played a significant role in the fire's outbreak, the report touches on the possibility that incomplete works to install a new gas riser may have contributed to the spread of smoke.
It says: "In those circumstances it will be necessary at Phase 2 to consider whether the installation of the gas services complied with the relevant regulatory regime, but the focus of those investigations can be relatively narrow."
The report also dismisses an early suspicion that the fire could have been started by an electrical power surge, with the inquiry confident that its point of origin was a faulty fridge freezer in flat 16.
In the early hours of 15 June, the report describes how London Fire Brigade (LFB) contacted Cadent, to request assistance in shutting off the gas. This formed part of its statutory responsibilities.
Cadent staff arrived by 5.00 am, and awaited instructions from LFB.
Separately, Jason Allday, a Cadent emergency response team member who knew the area but was not scheduled to be working that day, arrived at the site at 7.20 am after seeing TV coverage of the tragedy, and took charge of the situation.
The report describes the choices Allday's team faced: closing the pipeline isolation valves (PIVs) immediately outside the perimeter of the tower; shutting off the gas governors serving the local area or cutting the gas mains in the streets adjacent to the tower.
In the event, the PIVs were too close to the tower to be accessible, due to falling debris, and it was impossible to close and physically isolate at least 10 gas governors to shut off the supply.
The team identified the three gas mains using software on laptop devices and hard copy maps. They chose three locations, on Grenfell Road, Testerton Walk and Station Walk, where it was safe to excavate the roadway and expose the pipes.
By around 14.00, Allday said it had become clear that gas was feeding the ongoing fire, as orange flames could be seen within the tower. At that point, LFB and Allday agreed that it was worth making an attempt to shut off the gas valves in the tower's basement.
Allday and a colleague entered the building with three LFB officers, but found that the valves were inaccessible and the conditions dangerous, with fears growing that the entire building could collapse.
After that, attention reverted to cutting the gas mains, using a system called "bagging off", or inserting bags into the pipe then inflating then to form a seal.
However, two of the sites lay within an inner safety cordon, while in the third location the pipe turned out to be thicker, and deeper under the surface, than the maps had suggested.
Work finished at 20.00 on the more straightforward sites, and at 23.40 at the third, ceasing the flow of the gas to the fire.