Microsoft Access 2003 Update Query to a null value

I have a database that tracks items and who they belong to for work. The
person and everything they have been given are entered into a form which
updates the appropriate tables. Every item has it's own table with the serial
numbers already listed and blank fields for a person's name and locker
number.The update query works just fine to fill this information in. Now, the
problem I run in to is when someone LEAVES. Their record is deleted from the
main table manually. However, I need to find a way to remove them from the
other tables automatically once the main record is gone. Any help?