Calendar of Events Southern Iowa's largest Fireworks display at Terribles Casino concludes exciting day. 7/4/2010 - The day begins with a Community Church service on the square 11:00 AM to noon. Carnival opens at 1:00 PM. Water Fights at 1:00 PM Little Miss Osceola Contest at 5:00 PM Band on the Square at 7:00 PM is Eternity Focus. The annual Gigantic Fireworks Display at Terribles Casino starts at dark.