WordPress at a glance
action is not described

make_delete_blog action-hook . WP 3.5.0

Fires when the 'deleted' status is added to a site.

Usage

add_action( 'make_delete_blog', 'action_function_name_4002' );
function action_function_name_4002( $site_id ){
	// action...
}
$site_id(int)
Site ID.

Where the hook is called

wp_maybe_transition_site_statuses_on_update()
make_delete_blog
wp-includes/ms-site.php 1241
do_action( 'make_delete_blog', $site_id );

Where the hook is used (in WP core)

wp-includes/ms-default-filters.php 90
add_action( $action, 'wp_maybe_update_network_site_counts', 10, 0 );