How about old age? What's the longevity of azaleas? Another guess that comes to mind, is that there is a mature tree(s) close enough that the tree's roots has literally robbed the azalea of necessary moisture/nutrients for so long that it finally declined.
drdawg (Dr. Kenneth Ramsey)
The reason it's so hard to lose weight when you get up in age is because your body and your fat have become good friends.