First time here, so be kind with me, if this not the right forum to post.
I have (maybe) experienced an electrostatic discharge (ESD) from a computer case some days before, and I'd like to hear your opinions on this accident.
A computer case at my work, was not plugged in the mains outlet and it has been approximately 5 minutes, that it has been unplugged and switched off. Only thing plugged in, was the 2 monitors through their VGA cables and I think there were both switched off but unplugged. The computer was a 7+ years brand name machine, with a 300 W, 100 - 240 V, 50 - 60 Hz PSU.
Upon lifting the computer case with both hands to place it beside the desk, accidentally it made contact with the cold heating pipe passing nearby on the wall. Suddenly some yellow sparks with sound occurred (similar to arc welding sparks effect). The same time, the circuit breaker turned off the power at another room of the building.
According to my knowledge, I did not felt something strange as being electrocuted or anything at all after this happened. The computer afterwards was only started if the power cable was unplugged and plugged in again, and the tech said there is no damage except form a mis-plaiced starting button cord.
My questions are: -What exactly happened there? Is it possible that have being exposed to any electricity risk for my health with afterwards effects? -Why does the circuit breaker turned off?
Thank you all for your time reading this, and looking forward for any opinion.