Not a bad idea ApS. A 911 call will go through. NoBozo, I happen to have a retired cell phone that has a 911 button. I even think that I might have a waterproof bag thingy for it.
I'm with Chaselady. Keep the doors locked!
A combination type deadbolt might be a good idea. You could give rescue the combo, so they don't have to break down the door.
BTW, I am only 48 and often wish that I had a grab bar. Yes, I already have the no slip strips. Maybe it's time to upgrade them though.