The Speed Art Museum began demolition today to prepare for the construction phase of its $50 million renovation and expansion with the announcement of an additional gift from the family of Louisville philanthropist Christy Brown. The $18 million donation, the family’s largest, will accelerate the completion of all three phases of the master plan designed by Los Angeles-based firm wHY Architecture, including a new 9,500 square foot South Building to house a state-of-the-art theater.