Many buildings have progressively (pancake) collapsed due to fire damage. WTC is not the first by any means, and won't be the last. It's not uncommon.
That's not true, please provide evidence. As far as I am aware No high Rise in the history of the world has ever collapsed due to fire, let alone pancake collapsed into it's own footprint. The only documented cases of high-rise buildings undergoing complete collapse involved either controlled demolition or severe earthquakes. Of those, only controlled demolitions have caused such buildings to fall vertically into their footprints, leaving relatively small rubble piles, as was the case with WTC 1 and 2, and Building 7. Nearly all building collapses not involving controlled demolition are partial rather than total.
The One Meridian Plaza Fire
The First Interstate Bank Fire
The 1 New York Plaza Fire
Caracas Tower Fire
The Windsor Building Fire
The Beijing Mandarin Oriental Hotel FireAll these high rises were ravaged by fire for far longer than WTC and they never collapsed. The total collapse of steel-framed buildings appears to be an extremely rare event, even when large earthquakes are involved. In the Kobe and Mexico City earthquakes, many such buildings were severely damaged, and some experienced partial collapse. A 21-story office building in Mexico City appears to be the only such structure that has suffered a collapse described as total as a result of a stress other than controlled demolition.

This is what building look like when they collapse due to earthquake.