The landscape of downtown St. Louis will change dramatically starting Monday, when a wrecking ball starts knocking down Busch Stadium. The St. Louis Cardinals announced demolition plans Friday for the ballpark that has housed the team since 1966. A 10,000-pound wrecking ball will be used to knock down the southern half of the ballpark over a 60-day period. ``Twenty-four hours a day, seven days a week, we will be demolishing the building,'' Sid Perkins of Hunt Construction Group said.