* attacked, or null
     * @param cs A <code>ChangeSet</code> to update.
     */
    private void csSinkShip(Unit ship, ServerPlayer attackerPlayer,
                            ChangeSet cs) {
        ServerPlayer shipPlayer = (ServerPlayer) ship.getOwner();
        cs.addDispose(See.perhaps().always(shipPlayer),
            ship.getLocation(), ship);
        if (attackerPlayer != null) {
            cs.addAttribute(See.only(attackerPlayer), "sound",
                            "sound.event.shipSunk");
        }
    }