I'm wondering if what was being seen early on, say over California, before the big breakup, was a bunch of the tiles coming off. I'm pretty sure I've read that when we watch these dramatic meteor showers like the Leonids, many of these objects are the size of grains of sand. If this is correct, something the size of these tiles could put on quite a display as it burns up there. If a bunch of them starting coming off from near the front and hitting other more aft areas of the aircraft, you'd be talking about 12,000 MPH projectiles that could've done serious damage. This is all pure conjecture on my part.
MM