Believing the water flow to the reactor to be blocked by a closed valve somewhere, they went to the half-destroyed feedwater room on Level +24.
SNCF policy is to call for an engineer to examine the train (and who probably would have found the closed valve).
They reached the hatch in whose wall was a closed valve leading to one of the space life-boats attached to the hull.
After a painstaking search through the broken-up wreckage, investigators found a closed valve in the system that is supposed to supply air to the cabin.
The only closed valve would be that at the rear of the final car.
The closed valves that had prevented the auxiliary pumps from providing backup coolant at that critical moment were the result of human error.
Conventional injection engines can inject throughout the 4-stroke sequence, as the injector squirts onto the back of a closed valve.
This would normally be pressurised but with a closed valve, so that current pressure on the demand valve will not cause a free flow.
The weight of the blood continuously pressing against the closed valves causes them to fail, leading to vein distention.
The loss of these lives has been attributed to closed valves in the building sprinkler system.