Eloquent Relationship Problem

I have three tables. One is user, admin, super_admin. I have relationship with super_admin->admin and admin->user. Now the problem is when I delete a super_admin i can not delete all admin and users related to that super_admin. I can delete like super_admin and admin at a time and admin and user at a time. But I need to delete users, admins while I am deleting super_admin. is it possible in any way? Thank you.