A little crack can cause a mighty mess -- and a heap of disappointment. "The casino's closed today," Lucille Sfalanga told customer after customer Monday outside the Gulfstream Racing and Casino Park. A mysterious chink in the casino's floor-to-ceiling fish tank caused a deluge around 12:15 a.m. Sunday, forcing the two-story casino to close even while the village's shops, restaurants and racetrack remained open. On Monday, dehumidifiers and fans were at full blast, removing moisture from soggy carpets on both floors. Engineers were still trying to figure out what caused the leak, said Mike Couch, director of gaming at Gulfstream.