Re:
assuming their is no such thing as the death of the black hole and the death of stars(collapsing of stars) continue then black holes will keep on multiplying.....
I personally, now this is just my own theory, maybe backed up a little bit by what I have read about blackholes - I think that there really isn't a such thing as a "death" of a blackhole.
They now know that most of the trillions upon trillions upon trillions, of galaxies out there, they think that every single one of thse galaxies, has a blackhole in the center of them, helping them to formulate, and even exist in the first place, by their gravitational infuluence on surrounding star systems.
The light that we can see from our own, SagA blackhole, could possibly be the light that is traveling to us, from thousands upon thousands of years ago, in our own observations. So we don't really know how old most central black holes are, nor what happens to them when the stars that are in orbit around them, that form galxies, we don't know too much about their life-cycles, either.
I would take a guess that our neirest galactic neighbor, Andromeda, might also have an observable central black hole, but I would have no way to tell how to measure such a distant light frequency, that is sooo distant from earth.
There is some speculation, however, that many more 'mini' blackholes might exist anywhere. Though definitely not the size of something like sagittariusA, they still have some properties that could possibly change the fabric of time/space, that surrounds them.
Ok, I'm rambling - sorry, I get lost in my own head sometimes. I had a physics professor back in college, that one time told me that he winds up just getting lost in his own head, even when he's travling on an elevator, or something! - HA!
Cheers! -drew =P