The Save Venice fund-raiser began as these things do, with Bellinis, with tiny toast points topped with squid pâté, and with swaying musicians playing the greatest hits of Italian opera beneath a fresco by Tiepolo. Sequined women and tuxedo-clad men stepped out of teak vaporetti onto the private dock at Ca’Rezzonico where, it was hoped, strong drink and the thought of beautiful palazzi sinking into the sands below would lift wallets as easily as a child pickpocket in the  Piazza San Marco.<p></p><p>The organizers were salivating, greeting a German fashion designer, an American hedge fund owner, and a dour British playwright. Models had been hired to improve the beauty quotient, since billionaires are not especially attractive up close.</p><p>But just after midnight, something had gone terribly wrong. That was when, as one of the carabinieri put it, the <i>cascata dei corpi</i>, or human waterfall, began. It was a minor member of the Saudi royal family who went first, startling everyone around him by emitting a series of hoarse screams and then crashing through a glass window and plummeting out of sight. A billionaire American industrialist, who onlookers at first thought was rushing to save the Saudi, soon joined him. They were the first two.</p>