We have easily get the post titles from from the post Id. So We have to try to get the post Id using the post tags.
<?php
global $wpdb;
global $wpdb;
$postTags = "Accidents";
//Below query can be used to get the post id using post tags.
$querystr ="SELECT object_id FROM wp_term_relationships WHERE term_taxonomy_id = (SELECT term_taxonomy_id FROM wp_term_taxonomy WHERE taxonomy = 'post_tag' AND term_id = (SELECT term_id FROM wp_terms WHERE name ='$postTags '))";
$result= $wpdb->get_results($querystr);
//$result have the post id. Now we easily get the post title or post information using post id.
foreach($result as $postid) {
echo get_the_title($postid->object_id).'<br/>';
}
?>