|A serious line (mains) voltage surge could fry just about anything.. - even with a surge protector… Particularly if the surge protector has had a hit already - even a minor one.|
I know of one modem going out permanently after a lighting strike - and it had a surge protector in-line too!
Surge protector generally are best replaced after even a single hit - particularly on the domestic versions. More heavy duty/commercial versions may stand a few hits - before they too ought to be replaced. Some of the domestic protectors used to have a warning to this effect!.
If the situation was caused by someone working on the electric supply in your house…. then possibly you have a claim against them, and for some financial recompense - to cover your losses (they will have - or ought to have - suitable insurance)? They can/will counter you ought to have powered down/unplugged all sensitive kit of course, but who know you may be lucky and at least get recompense for a replacement computer?