I was going to back the videos up over several older smaller drives and connected an external usb drive adapter and something let the magic smoke out. Either the switched power supply blew the drive or the drive blew the power supply but both are toast

.
There were some really good helmet cam videos on there, crossing the mac with two views (from the wheel and helmet), the parade of bikes to Bellaire, some rodeo video (some are probably happy that's gone), tunnel of trees etc, etc. All said, there's more than 100GB gone.
Only option is to ride some more and make new ones

. Maybe back up a little more often too.