This was something weird that happened to my father. He had both a desktop and a laptop in his bedroom. When he tried to turn on the desktop computer, there was a large spark in the back of his computer, and the power source was blown out. Next, he turned on his laptop, and the same thing happened. Boom, out of comission as well. The weird thing was, the laptop was running on battery, and not plugged into the wall. He installed a new computer later, and it works just fine.

Totally confused as to what could have happened.