Thunder Over Louisville, the annual kickoff event of the Kentucky Derby Festival, is an airshow and fireworks display in Louisville, Kentucky. It is generally held each April, about two weeks before the first Saturday in May, or Derby Day. In years where Easter Sunday falls on the usually scheduled weekend, Thunder is moved a week earlier. It is the largest annual fireworks display in North America and began as part of an opening ceremonies event in 1989 with daytime fireworks. 1990 brought the first nighttime fireworks event. It officially began in its current location along the Ohio River in 1991 with fireworks, and an annual air show was added in 1992. Thunder generally starts in the afternoon with an air show, followed by the fireworks show starting at 9:30 PM, along with a synchronized soundtrack through PA and radio. An average of 625,000 people have attended each year since 1997, lining the banks of the Ohio River in Louisville, and across the river in Jeffersonville and Clarksville, Indiana. Some also watch from the river on boats, docked in positions auctioned off for charity. Eight 400-foot barges launch the fireworks, provided by Zambelli Fireworks Internationale, from both sides of the George Rogers Clark Memorial Bridge (Second Street Bridge), and more fireworks are launched from the bridge itself. In the twenty-first century the estimated attendance at Thunder has usually been approximately five times that of the main attraction, the Kentucky Derby horse race at Churchill Downs. History Thunder Over Louisville began as a concept at a Kentucky Derby Festival workshop in the summer of 1988, after a decision had been made to have opening ceremonies for the first time. The first opening ceremonies were held in 1989 at the Chow Wagon on the river and broadcast live to the They're Off! Luncheon crowd at the Galt House East. Organized by multimedia producer Wayne Hettinger, owner of Visual Presentations, they featured a live stage show to introduce the festival theme song and the release of about 20,000 multicolored balloons—followed by daytime fireworks. Attendance was estimated at 10,000. The first nighttime fireworks show was in 1990 at Cardinal Stadium in the Kentucky Exposition Center, where more than 35,000 people attended a Derby Festival opening ceremonies concert by Janie Fricke and a 4,000-shell fireworks show following a sold out Louisville Redbirds baseball game. Fireworks had been used in Derby festivities since the 1960s, but the