Delete all comments from a WordPress post

delete_all_comments.php

<?php

/*
- Save this PHP file to the root of your WordPress website
- Log in as Administrator
- Change the post ID on line 13
- Call the PHP file it directly on your borwser
*/

require('./wp-load.php');

if ( current_user_can( 'manage_options' ) ) {
	if ( $comments = get_comments( array( 'post_id' => 16057 ) ) ) {
		foreach ( $comments as $comment ) {
			echo '<p>Deleting comment '.$comment->comment_ID.'</p>';
			wp_delete_comment( $comment->comment_ID, true );
		}
	} else {
		echo '<p>No comments found</p>';
	}
} else {
	echo '<p>Not allowed</p>';
}