A connecting rod locks up due to debris getting wedged between the crankshaft and the big end of the rod, and torque throws the piston through the cylinder wall and the water jacket. Then the rod breaks off and the remains of it hammer around inside the crankcase. Keeping the oil clearance close enough to prevent the rod hammering on the crank journal prevents the damage that gets the process started. It was called called "throwing a rod" and it usually happened at high RPM on a heavy pull, particularly on big truck engines where lots of vehicle inertia helped the piston exit the engine.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!