Mine was catastropic and without warning. Like Bundas, however, I has just tried to show a friend how the car would take off like a rocket when the MSR is turned off. The car just didn't respond like it usually does, but I attributed this to the clutch slipping I had been experiencing. Anyway, a 1/4 mile later I parked it in his driveway and when I came out to restart it it was dead. Not sure if the try for a fast launch helped the F1 pump to fail, but the coincidence is weird.
Luckily I hadn't blocked his cars since my car was immovable and had to eventually be pulled onto the flatbed with trolleys under each wheel. I shudder to think about some of the less hospitable situations where this might have happened!
Mike