Engine Blow-Ups

[motto]

The airline I worked for had Hobart Ground Power Units (GPUs) to provide electrical power to the aircraft when on the ground for any length of time. They were powered by six cylinder Cummins diesels that ran at fairly high revs for many hours at a time.
One night when we were about to go home the steady, constant drone of the GPU just outside the hangar suddenly developed an accompanying knocking sound that rapidly got louder until there was a very loud bang followed by silence.
We went down to have a look and couldn't help noticing the large pool of oil underneath the unit with a liberal amount of engine fragments scattered about in it. We released the hand brake and rolled the vehicle aside to have a closer look at the debris and were surprised to see a con-rod bent into a U shape laying there. The puzzling part was that the gudgeon pin was still in-situ, through the small end. I guess that the piston must have completely broken up.

David