Why do I get error "Failed to destroy your database Yikes! The database was not destroyed due to an internal error" when trying to destroy the database?

Issue

Receiving error when trying to destroy Heroku Postgres database:

Failed to destroy your database
Yikes! The database was not destroyed due to an internal error.

Resolution

Customers receive this error when the Heroku Postgres database is shared/attached to some other app, in order to destroy the Heroku Postgres database you will have to detach it from the shared app and then re-try database destroy.

Debug Commands:

heroku pg:info --app sushi
heroku addons:detach HEROKU_POSTGRESQL_[COLOR]_URL --app sushi
heroku addons:destroy HEROKU_POSTGRESQL_[COLOR]_URL --app sushi

Documentation:

Sharing Heroku Postgres between applications
Removing the add-on