Ford Repair: Tampering?, fuel pumps, fuel pump

Question
Don't have a Ford, but do have a general question.  Can a fuel pump fail instantly, fine one minute and nothing but stalling the next.  My daughter's fuel pump 'failed' while at an oil change.  We have it now w/ an honest shop.  New shop says it's the fuel pump but they also say no evidence of tampering.
COULD this failure have happened without tampering?  This was a well-maintained car, running great.

I'd appreciate your opinion and any suggestions on how to proceed.  Thanks.

Answer
Jean-

  While it's not how fuel pumps usually give up, it can happen.  Normally fuel pumps will whine...loudly...for a little while before finally giving up.  But sometimes they can just die.  I'd believe the honest shop if they say there's no signs of tampering.  Hope this helps.

Steve