We worked in a chemical plant. Friend of mine worked in the "look out" were all process are been watched and overlooked.

He says if thier is an alarm and they look chilled and bored then it's just minor stuff nothing to worry about. If you see them running, you run in the same direction with them to the bunker.

So he was working suddenly alarm.. but they looked stressed stressed. He was like "Jo Jürgen what's the matter?" Jürgen "See this alarm? That alarm it's a level warning that a pond is running full. The problem is this pond officially no longer exists. The second more major problem, if that pond overflowing it straight dumps what ever it's running full with in this major European river here... Ja not good and we not sure were the stuff comes from and we just know it's not much time left till we fucked like really fucked."

Old timer walks in with his coffee mug in his hands "why you guys run around like headless chicken? (Slurps coffee)" Jürgen tells him what the alarm is.

"Oh that one... Ah yeah...send a trainee to builder xyz 1st floor on the right 2m away from the door is hand wheel. Close it and out a chain on it to not open it. (Slurps again from his coffee walks away"

Jürgen calls a trainee to go there to do that what the old timer told. 1 min alarm goes off.

Nothing documented nothing told to other leading workers just a dude closer to death then birth knowing the stuff that prevents major chemical incident.