Sin City blew a kiss goodbye to the Tropicana before first light Wednesday in an elaborate implosion that reduced to rubble the last true mob building on the Las Vegas Strip. The Tropicana's hotel towers tumbled in a celebration that included a fireworks display. It was the first implosion in nearly a decade for a city that loves fresh starts and that has made casino implosions as much a part of its identity as gambling itself. The casino came down with a seven-minute celebration involving 550 drones and 150 "pyrodrones" counting down to the controlled demolition of the resort originally...