Plugin placement to delete user from another table?

[bigtime]

Hello,

What plugin hook location do I need to insert the code to delete a user from a non-vb table when deleting the user from the admin panel?

Here is the code I'm using at userdata_delete:

PHP Code:

$db->query_write("DELETE from review_users 
    WHERE username='$username'"); 


It is resulting in a blank page and the username is not removed from review_users.

Thanks.