I'd recommend having backups of anything you aren't ready or capable to easily redownload on external HDs that aren't running 24/7. I like to presume not being turned on all the time prolongs their life, seeing how I have a couple of usb2 externals that still work, as much as the usb2 interface can be considered to work in 2024, being as slow as romance in a shounen manga.

Still, lousy luck to lose both like that. Smells like either planned obsolescence or your PC (PSU) sending a power spike the HDDs' way to fry them.