How big was Ancalagon?

[Puddleglum]

Originally Posted by Ibrîniðilpathânezel

On the other hand, there is some precedent for Tolkien's fiery critters breaking mountains when they fall and die.

Originally Posted by Ibrîniðilpathânezel

Then again, maybe when these fire-critters fall and die, they explode in a nuclear fashion and flatten the landscape.

It's the "Dark Side" energy being released when they die <g>

Seriously, if you look at the other dragon deaths which Tolkien described, I think we have to allow for more than just a dead weight falling.

• When Glaurung was mortally stabbed, he started thrashing around breaking things.
• When Smaug received his mortal wound he shot spouting into the air, crashed down on Esgaroth, and completed the total destruction of the town by his death-flailings.

Also, if the "three peaks of Thangorodrim" were more in the style of mighty towers of slag and ash - then think how it only took a single Boeing 767 to bring down each of the WTC Towers on 9/11.
All it takes is for a thrashing Ancalagon (mightiest of the winged dragons) to weaken the supportting infrastructure of the towers enough (in his death throes) that they collapse under their weight - not unlike the WTC towers.