I clicked on RickF's link to the tweeter pics but had to click back a few pages to find the right post. This should be a direct link.

http://www.axiomaudio.com/boards/ubbthreads.php?ubb=showflat&Number=286101#Post286101

Sure looks like the dome itself shattered. Never seen anything like that before - although I have seen a couple of *melted* domes in my years.

M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8