Many years ago I took a training course for a fancy Engineering Drawing program on a Unix workstation. Our company had an emergency, and the manufacturer kindly set up a class with double the size they regarded as their maximum. The classroom was filled with Unix machines strung together with Ethernet cables and AC extension cords.
About an hour into the course, a student in the back of the room asked “Is there anything you have to do before you shut down a UNIX system?”
”I’m glad you asked,” replied the instructor, launching into a discussion of the importance of a graceful shutdo...”
”Because the machine is on fire!” said the student.
We turned to see smoke pouring out of a machine and even flames. “PULL THE PLUG” yelped the instructor.
When the smoke cleared it was obvious that far too many UNIX machines had been connected to the same AC circuit.