user ability to delete from river activity

this is an admin option in 1.8.8, i would like to make it an option for my users also.  I know the action code must be modified:   elgg_is_admin_loggin_in

but the x (delete icon) does not appear on a users activity page, and i have looked and looked and cant find the code for it anywhere.

lots of google searches only return plugins and comments for 1.7,

any help anybody?