Disk erase failed

@johnnnw:

I guess you ran Disk Utility from your internal disk.

If this is the case it might also be an error from the binary Disk Utility.

To eliminate this possibility, I suggest you to run Disk Utility from your recovery volume:

1. shutdown, if it fails crash it: button off / 5 seconds,
2. reboot while holding [⌘]+[R],
3. select Disk Utility and check your full disk.

As @Daniel Azuelos mentioned or Create A bootable Installer of macOs version ?? ( your chose as long as Catalina of above ) boot from it and use Disk Utilities to perform the Erase

It's possible it failed.

If it doesn't show up in Disk Utility, it would seem that it is not working.

Recover what?

The data? I thought you were erasing it.

The drive? Even if you could make it work for a moment, why would you trust it for anything.

Nice advice @P. Phillips!

@johnhw : a bootable Installer is a very precious tool to build. I have a collection of them and they all rescued one of my Mac or a friend's one.

Personnal advice : use only 16GB USB keys of quality, because you won't put anything else on it, and you have to trust it.

Tend to agree regarding a Failed Internal drive. Apple Repairs have them do a Diagnostics

Unfortunately your diagnostic is now correct!