I have to agree with the subject. It's also difficult mistake to make, it should have been obviously wrong
just by looking at it before reconnecting the power.
There is likely colateral damage: the GPU, the mobo (if you're lucky only 1 dead slot), the riser.
Test everything seperately to be sure.
Mistake is mistake, I'm guessing OP is a newbie to crypto mining, that can be another reason for the easy mistake, now I'm sure such will never happen again because it's going to be painful to lost such valuable item just like that, OP will learn big from this