2-4-D....that'll get rid of it.
Mix carefully.
I had a patch of Bermuda grass that had some weeds in it out front of my house last year, and was making some pasture spray to kill some broadleafs. While I had my rig there mixing, I gave it a good wanding. Killed everything. Bermuda included.
I had the mixture set for a certain flow rate at a certain speed in the pasture, and evidently applied too much with the wand out front.
Good news is that Bermuda is hard as hell to kill, and now it's back to normal. But it sure looked like hell all last spring and summer.