The 25th anniversary edition of Kaboom Town, the major-league fireworks display in Addison, Texas, went off as planned yesterday, despite intermittent rain and everpresent mud. The event cost the town an estimated $240,000; $50,000 for fireworks $55,000 for police overtime, with a historic warbird flyover, and a free movie afterwards. The Dallas ex-burb has been hosting the event for 25 years. The show, recommended by the American Pyrotechnics Association, attracts about 400,000 people each year.