Wow. Thanks. A couple of thoughts. As to the router, many people forget to use an UPS. Since the modem, switch and router are all three important things, you may as well use one. My recommendation (highly) is Cyberpower. I have had no luck with APC. When you look at any, consider getting the AVR versions. Those are Atomated Voltage Regulators. It isn't just the surge, it can be the brownouts, so this keeps the voltage in a steady 95 to 120 range.
But, you reminded me of something I should do but I have never gotten around to it. On my UPS, there is an Ethernet port in and out, so that the Ethernet cables from the jacks are covered as well. Given your description, the high voltage could have traveled down your cables. My only concern is if they are Cat6 and can run at 1Gb/s would the Cyberpower UPS be the weak link.
Now on to your router. Are all of your computers connected directly to the router?
