Question
We live in Ohio and have had a hot summer so far.  My Francois Rabelais floribunda rose bush is dying suddenly.  We have kept it watered but the canes are turning black as are the leaves. What little roses started to bloom are tiny and shriveled up...please help!!

Answer
When a rose bush goes the way yours is doing, then there is a serious problem with the roots that is causing it to die as you have described. Because a rose is a shrub, it does take a couple of months for the problem to be seen. Not seeing the rose, here are some examples of what can cause the rose to act the way yours is.
Verticillium wilt...a bacteria in the soil that gets into the sap of the rose and kills it quite suddenly.
Cane canker...fungus spores get into the canes during the winter but wait until it is warm to grow and kill the canes. usually starts from the top or where there is damage on the canes.
Something in the soil but it would probably effect other roses too.
Crown galls...growths on the roots that stop nutrients from getting to the canes. Dig down and see if there are any nodes on the roots or even near the base on the canes.
Your rose really should be dug up and not planted again as there is a problem that will keep re-appearing no matter what you do.