[XBob]

that is definitely a 'tile' probably from underside of the wing

[Lady Jag]

When tiles started coming off the drop-offs probably would have risen exponentially. I.e., a tile comes off, allowing heat to the area, heating the tile adhesive and creeping under adjacent tiles, further loosening adhesive, and so on.

I have a tile and it is amazingly light weight. It is also granular to the touch and you can rub off the granulation; you could destroy the tile that way. Their heat resistance and extremely light weight accounts for their landing almost intact rather than evaporating.