Deleting an account message stuck

I deleted an old account on my MacBook Air, (not the one I'm logged in as) it never finished deleting the account. I still get the "deleting account message".

System Preferences won't close, and I can't force quit system preferences either - I get a message saying it's deleting an account.

It's been a couple weeks since I originally started the account delete process, something is obviously wrong. Everything else works normally, but I'd like to clear this message and close sys pref.

Anyone seen this before? Or ideas to try to resolve this?