Hydrangeas: Hydrangea wilting one branch at a time., 0 by Lono

Lono wrote:
A few weeks ago, I noticed a single branch of my hydrangea wilting. After a while, I cut it back because I realized it wasn't going to perk up. Now another one is wilting. The rest of the bush is doing fine, except for one set of blooms that seems deformed. This bush isn't nearly as tall or as healthy as the one that's 10 feet away in the same bed. I don't know whether this one is diseased or has some sort of boring/ burrowing pest.

What really made me sad is that this was the only branch that was blooming blue. All my others are pink.

Has anyone seen this before?