As of now, it is possible to delete the only user that has administration rights in a Space without realizing it.

This is an issue especially for the OnDemand users, as without the sysadmin rights, they lose all administrative access to a Space and can only regain it with Support's help. It would be handy to have a warning displayed upon an attempt to delete the only admin user, informing that it would mean losing admin access to a Space.