It's nothing but a series of escalating tragic events with vague warnings for the need to be vigilant and safe on the job.
Funny in a very dark way. I found the link from a coworker. The person who posted it on YouTube claims to have seen the video in an actual safety training. I hope this isn't actually being used to train.
We know from disaster experts like Amanda Ripley that specificity, to the point that your unconscious mind can picture yourself succeeding in dangerous circumstances, is imperative to succeeding in risky situations. I can't image a video like this does much besides sensationalize and scare.
But in its own way, it sure is entertaining.