Prop wears out?

So we are riding yesterday, when all of a sudden, a pronounced vibration start up. We didn't hit anything, figure that we might have a rope wrapped up. Get home, check it out, and the prop is loose on the shaft. I'm thinking that's weird, event if the nut backs off, the prop is pretty much on there until you get the puller out. Then I check it out, the trailing edge of the prop is bent back out toward the end on all the blades, one really pronounced, the others slight to moderate. No marks ot nicks on the prop at all, otherwise perfect. Have never had this happen before, has anyone else? Did I just wear it out after pushing a lot of weight over the past 3 years?