The box office was hit by a double whammy over the weekend. Not only did it have to suffer through the usual lackluster attendance over the Labor Day holiday -- the only major holiday of the year when attendance traditionally falls -- but it also was hit by the oncoming Hurricane Gustav. Along a wide stretch of the Gulf Coast, movie-theater owners shut down. Those who did not watched many of their patrons evacuate their neighborhoods and take up lodgings in inland emergency shelters; they would not have been in the mood for a night at the movies. Of five new films entering the box-office fray, not one earned $10 million or more. The only film that did was the action-film parody Tropic Thunder with an estimated $11.5 million, which put it in first place for the third straight weekend. It has now taken in $83.8 million -- but the $90-million film is a long way from breaking even after payments to theater owners and the cost of distribution and marketing are taken into account. Babylon A.D. came in second with an unimpressive $9.7 million. (By contrast, the latest Halloween sequel opened a year ago with $26.4 million.) The Dark Knight moved back to third place, taking in $8.8 million and bringing its total to $502.4 million. It is only the second film in history to climb past the $500-million mark and now takes aim at the other one that did -- Titanic , which wound up with a domestic total of $601 million. Few analysts if any, believe that Knight will be able to sink Titanic 's record. Warner Bros. distribution chief Dan Feldman said Sunday that he expects the film to finish with about $530-550 million.

The top ten films for the weekend, according to studio estimates compiled by Media by Numbers 1. Tropic Thunder , $11.5 million; 2. Babylon A.D. , $9.7 million; 3. The Dark Knight , $8.8 million; 4. The House Bunny, $8.3 million; 5. Traitor, $7.9 million; 6. Death Race, $6.2 million; 7. Disaster Movie, $6.2 million; 8. Mamma Mia, $4.4 million; 9. Pineapple Express, $3.5 million; 10. Vicky Cristina Barcelona, $3 million.