Unlike a lot of Jalopistas I'm not a fan of diesel engines. Here's what happens when a diesel engine decides it doesn't want to die quite yet. (The original video won't embed on Kinja as it's a Liveleak vid)
It knows it will die soon so goes on a noisy, smokey rampage.
Noise and smoke are all well and good but not when the noise is diesel clatter and the smoke is full of particulates. This engine was running all by itself - even with the ignition turned off.
The devil's juice doesn't use spark plugs to run, it relies on compression. The only electrical aspect to making a diesel engine run is in the flow of fuel. But when oil mist gets in to the combustion chamber of a worn (knackered) diesel engine the engine can continue to run until it seizes.
The only ways to stop it are to block the supply of air, by blocking the air intake, or to put it in gear, with the brakes on, and stall it.
Or don't buy a diesel in the first place.