Get a database admin to create an admin account
Log in with that admin account
Use that admin account to delete a work (or edit the work's tags, or anything else that would show up on the admin activities page)
Get a database admin to delete that admin account
Log in as another admin
Follow the "Activities" link in the teal admin navigation
You'll see a table, and one of the items in that table will say "Admin deleted" in the Admin column. Find that item, and follow the linked date that corresponds to it
A 500 error
What should happen
The page should load, but it should say "Admin deleted" for "Admin"
Followed the date links for two deleted admin accounts' activities; got a detail page and no error. Looks good!