External SSD may have failed. Options?
I'm assuming that you tried to connect the USB enclosure directly to your Mac to eliminate the USB hub as a point of failure. If you haven't give that a shot as your hub may have taken the brunt of the surge
If it still doesn't work, there's a good chance that your drive may be fine but the USB to SATA interface of the enclosure got fried.
For a "quick and dirty" fix, get a USB to SATA adapter. I keep one of these handy for doing all sorts of diagnostic work exactly for exactly the scenario you are experiencing.
This is basically a USB enclosure for your SSD without the "enclosure" part. You will just need to open up your existing enclosure and remove the drive. Don't worry about damaging the enclosure, right now it's dead and you're dead in the water if you can't get your data. Just be careful not to damage the drive or the drive's SATA/power connectors.
Once you have the drive extracted and connected, you should be able to access it like you did before.
This bring us to the points that bears repeating...
Always make backups of your Lightroom catalog. If on assignment, do it daily. I am totally an amateur photographer and I back up my LR catalogs every time I open LR.
You learned (unfortunately) the hard way about power surges. When that generator kicked on it probably sent a surge of current down the line. A backup generator doesn't provide the nice, clean power you've come to expect from the utility company. Get a quality surge protector (like APC) or better yet, get a battery backup (again, like APC) to sit between your outlet and your expensive equipment. It's much more cost effective to have a $100 UPS die than all your equipment and work.