You can find the details about it here:
http://en.wikipedia.org/wiki/American_Airlines_Flight_191
http://www.youtube.com/watch?v=xTAdt-6ff3I

Mechanics used a forklift to remove the engine and pylon - they changed
shift in the middle of the procedure and had not positioned the forklift
correctly.
The forklift pushed up on the assembly and jammed the engine pylon
against the wing mounts cracking and bending the pylon. (The bolts did
not fail.)
The loss of the engine ruptured the hydraulics for the slats on the wing
that lost the engine - the lost engine also powered the slats warning
light and pilot's stick shaker.
In addition, the training manual had incorrect procedures for what to do
in the event of a loss of slats, which the pilot followed and it made
the situation worse.

As stated in the book "Airframe" by Michael Crichton,  accidents are
rarely caused by a single event, but by a series of cascading failures.

Of course, if you want to find an example with parts failure, check out
Atlantic Southeast Airlines 529

Todd

On 6/14/2012 8:10 AM, Robert Stevens wrote:
> A "member" (of something) wrote:
>
>> A number of years ago a big airliner crashed after losing an entire engine and pylon in flight. The engine mount bolts were thoroughly sourced, checked, tested, and the alloy composition tested. The bolts should  not have failed, but they did. Why?  In the end, it was found that it was the mechanics fault. Instead of following procedure, they were short cutting and using a fork lift to make it easier to make an engine change.
> In this case, it is very advisable to observe the installation procedure of your alternator, and if a forklift
> is being used, be suspicious. If a forklift is NOT being used � context really is everything.
>
> bob �.