I know two folks with E450 based Motorhomes that had the fuel pump go bad. In both cases the pump failed at startup. For both it happened while the Motorhome was parked in the driveway. They had no signs previously that it was failing.
The one time I had a fuel pump fail was while towing our Hybrid TT with our Astro Minivan. We were going up a tall bridge. As we neared the top, stepping on the gas pedal did nothing. I tried again and the engine revved and all seemed fine. At the bottom of the bridge, there was a T intersection with 2 lanes turning left. We were in the right lane of the 2 left turning lanes. Just after we made the turn onto a 2 lane highway with a slight grade the fuel pump failed. I had enough momentum to get into a right turn lane into a parking lot before forward motion stopped. I didn't make it into the parking lot unfortunately.
-Michael