Some 10 years ago, I was working on a project for a major telecomm company and needed multiple sources of rs232 data to test an implementation of x25 over ethernet. Having scrounged all the unused (i.e. old) laptops and PCs, I added a couple of ancient RS Model 100 portables to the mix. Programmed in BASIC and running at 300 baud, they weren't fast but did provide a steady stream of connect, transfer data, disconnect operations - including audio alerts (beeps when the link was unavailable).
It all ran fine for several months while other loading was added to the backbone network. Much of it came to a smoking halt the day the 40KW UPS was installed It was a 120/240 split circuit and the electricians had swapped the hot and the neutral on one side of the 120. Lots of groaning from the bigger Cisco hardware, smoke from the PCs, and the smell of overheated electronics all over the lab. Some of the laptops survived, but the desktop PCs and the Model 100's did not.
Not a problem that had been anticipated, as the same crew had done other electrical work with no problems. Testing was set back while alternate sources of rs232 data were acquired and the Cisco routers and switches were checked for possible damge.
Errors like this ultimately fall to the in-charge electrician, who was asking what he could do to help that day as he likely would be fired the next day - the electrical company was responsible for the $1000s in damges to the network equipment in the lab.