..but will also add that all engines fail (some catastophically, some related to surface wear), and they fail (IF all parts made exactly the same)  at fairly reproducable rates.  The term "blow up" may not be the best choice of words, but i used it to get my point across- your right in stating most failures are related to surface wear, as nearly all parts are designed below the fatigue limit, and ussually by an  order of magnitude.

These rates changes over time, and most lifetime curves include a inititial failure rate related to faulty parts batches and such.  These often are the one to get recalled, but in the long run have little impact on median expected engine life.