This is a photograph of the fireworks display during "Thunder Over Louisville." This event, in Louisville, Kentucky, takes place every year in mid-April, two or three weeks before the Kentucky Derby. It marks the beginning of the city's Kentucky Derby Festival. This is one of the largest fireworks displays in the country each year. They use 8 barges in the Ohio River along with launchers on the bridge to create a huge display. Hundreds of thousands of people line the banks of the Ohio River to watch an air show during the day and the fireworks at night during Thunder.