It happened about a year ago. It was a Crucial, well known for their stability and quality control, too. They suggested at first that it could have experienced power levels outside of its parameters and shut itself down, and suggested I try several cycles of steady power followed by shutting off. But, this failed to have any effect. They ended up replacing it under warranty at no cost other than mailing them the old, dead drive. (The new drive has not had problems.)
Since I could never get it to boot up, I could neither purge its contents nor retrieve them. Since I am already in the habit of multiple backups including cloud storage of all new files and periodic archiving, I did not lose any information that could not be replaced. I just had the tedious chore of re-installing the OS and each individual program, including calling Adobe about two programs that had to be activated over again, since I did not de-activate the lost installations. For that reason, I am adding periodic OS drive backups as well.
This one tip will help you sleep better tonight
A few seconds are all you need to get a better night's rest.