system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What really happens when everyone in a building flushes their toilets at the exact same time?
gpt
We did this at our High School back a lonnnngggg time ago. After a few unsuccessful attempts due to lack of timing we initiated "Operation Royal Flush Phase IV".  At the bell all toilets were to be flushed, all taps turned on at the sinks. All tolled there were probably two or three hundred fixtures.

At the bell we all did our thing...I was in the B-200 wing Men's washroom...

Flush.......a slow gurgle.....the water down the trap then........nothing..........then....... a low rumble.....then.....you could feel it coming.......every toilet and sink literally exploded with regurgitated liquid.....hitting the fan......omg nothing so grand had ever been seen before it was a total success. Even more so as they had to close the school for a week to get it back in shape....