My working theory of what caused the fire, based upon a bit of safety experience and research:
In 2013, residents reported massive "power surges" throughout the entire building, causing smoking outlets and destroyed electronics and appliances. This is a classic symptom of ground arcing due to a loose neutral in the building electrical system. A loose neutral is a severe fire hazard that can cause unbalanced loads, burned-off insulation, eventually leading to 1000-degree F (600-degree C) flashovers.
Additionally, the water pumps were reported tripping off, leading me to believe that the pumps may have been recently replaced with newer models that drew more current across lower-rated wiring and may have caused voltage sag. The voltage sag would increase the oxidization cycle of loose neutrals, thereby heating wires and carbonizing insulation. They should have checked every single outlet and breaker box in that building.
Initial reports from the site spoke of a resident who said they had a refrigerator "explode," causing the fire to spread rapidly. This could have been hyperbole about an arc from a power outlet due to compressor loading. Or it could have literally exploded, if the refrigerator was recently replaced with a "bought on the cheap" green-energy unit that was leaking isobutane or propane as its refrigerant gas.
The fire would have then rapidly combusted upward along the ceiling, spreading outward, breaking windows due to intense heat and caught the outside cladding on fire along the edge of the building between the concrete fascia and the aluminum panels, which was likely a cheap foam insulation cited in numerous high-rise fires. The insulation would have vaporized the aluminum at high heat and fed the fire as it progressed up the outside of the building into the units.
Residents reported problems with the fire safety system, and no fire alarms or or sprinklers were activated at the time of the fire. Either the sprinklers had not been replaced or there were no sprinklers to begin with. Sprinklers would have helped with damage-control to the structure, but would have made little difference if residents couldn't get out of the burning building. There were also reports of a lack of fire exits and inadequate stairwell lighting.
All in all, a perfect storm of regulatory corner-cutting. Read the Grenfell residents' activist blog: eye-opening the problems they had prior to the fire. Now a horrific nightmarish monument to the corruption of the wealthy, in one of the richest neighborhoods in London with some of the greatest income disparity.
This whole thing reminds me of the Triangle Factory Fire in NYC that led to the New York Fire Code model. IN THE YEAR 1911. It appears the richest among us are too lazy to learn. And too stupid to listen.
See information below for industrial and fire reports with similar behaviors, especially the last link:
POWER SURGES, ELECTRICAL APPLIANCE FAILURE, PUMP FAILURE CAUSING GROUND ARCS?
GROUND ARC FIRES CAUSED BY LOOSE NEUTRAL:
CASE SAMPLE EXPLANATIONS OF LOOSE NEUTRAL SYMPTOMS AND FIRE:
REFRIGERATOR THE CAUSE OF FIRE?
FLAMMABLE CLADDING DOESN'T MEET FIRE CODE OR INTERNAL SPRINKLERS ARE INADEQUATE :
EDIT: spelling and links