https://www.youtube.com/watch?v=d_8Fc9qAZcw
Look out! This very large turbo diesel apparently has had enough of this dyno run. After just a short run, although at very high RPM, the entire top end explodes skyward. The smoke maybe should have been a hint at what was to come but no one ever expects this catastrophic of a failure in the sterile conditions of a lab. These technicians sound like they jumped out of their skin.
Related: The dyno couldn't even handle the torque of this custom creation