There was a documentary on British TV on the 14th anniversary of the WTC attacks that presented yet another 'compelling scientific explanation' of how two modern steel-framed skyscrapers could collapse just a couple of hours after being struck by airliners.

The new theory is required because there is still no consensus as to what caused the steel frames to melt:

1) The girders were thermally insulated and most fire-protection engineers dismiss the idea that the original impact could have stripped the insulation from the steel support-pillars

2) The jet fuel burned off very rapidly, limiting the temperature inside the towers to less than the melting point of steel.

3) Three explosions were heard by over a hundred individual firefighters just before each of the towers collapsed.

The two self-styled experts (one a chemist, one an aluminium smelter) claim that the aircraft fuselages survived the impact and entered the centre of each tower in substantial-sized pieces: these melted and reacted with the '...vast amounts of water' (not vast enough to put out the burning office fittings, apparently!) to produce hydrogen, which exploded.

Problems with this theory:

1) The NIST report is adamant that the planes were shredded into tiny pieces by the impact which could not have produced a sufficient quantity of molten aluminium to cause an explosion (If this were not the case - if the planes survived as a few major chunks - then why did this not occur at the Pentagon, where no trace of wings, fuselage etc were recovered?)

2) Why have the Port Authority (who hold the remaining WTC debris) refused to allow it to be examined for aluminium globules?

3) Why, then, did WTC7 collapse even though it had not been struck by an aircraft? Explosions were seen and heard here, also.

I'm not actively interested in the so-called 9/11 Conspiracy Theories, but I do know one thing: until the media (and the 'authorities') stop coming up with easily-dismissed 'explanations years after the event, many people will continue to conjecture about the credibility of the official explanation....