I agree- what renovation in a stone and mortar building would require a contractor to employ a cutting torch? The Muslims are becoming experts at destroying buildings, as we found out on 9-11 in NYC-- Just as the Japannese became experts at shallow water torpedeos vis a vis Pearl Harbor 1941. Even if the bearing outer walls remain somewhat intact (unlike the Twin Towers) future usage of the Cathedral may well be unsafe-- And as the Cathedral is the most often visited site by tourists in Paris, even outnumbering the Louve, the terrorists are experts at "blending into the mileu__ and not raising suspicion. My money says- terrorist attack- well planned as well.

"The field is the touchstone of the man"..