There's a lot of pictures of a similar issue. This guy had a 1080 that caught fire and he was basically doing the same thing. Unplugged the card, plugged it back in, turned it on and it broke.
https://www.youtube.com/watch?v=WAbl0fLY06UDoes it look like this by any chance?
It was discovered that the issue originates from the voltage regulation modules which overheat leading to component failure and MOSFET blow out. The issue affects EVGA’s entire range of Nvidia GeForce GTX 1080 and GTX 1070 cards equipped with the ACX cooler, all of which lack direct VRM cooling. This includes GTX 1080 & 1070 ACX, SC, FTW & FTW DT models. Essentially all dual fan models except the Classified.You probably had an older model that doesn't have vram cooling, which was causing the overheating of these cards. The later models had thermal pads installed on the ram chips to prevent this. If you have a model with no cooling, RMA it and you should get a new one.