Theme Crashed Site

I changed the theme which crashed site and am unable to change back/correct. Error Message:

Fatal error: Cannot redeclare bp_dtheme_ajax_querystring() (previously declared in /home/content/52/7491252/html/attitudesinreverse/wp-content/plugins/buddypress/bp-themes/bp-default/_inc/ajax.php:20) in /home/content/52/7491252/html/attitudesinreverse/wp-content/themes/bp-daily/_inc/ajax.php on line 63

Please assist....