Four people from Iowa are injured after a boat explodes at the 20 mile marker of the Lake of the Ozarks. On Tuesday afternoon, Osage Beach fire crews and the Missouri Highway Patrol responded to the Ledges Cove across from the Ledges Condominiums. Fire fighters were able to put the blaze out in about 15 minutes. The Highway Patrol says the fire also did minor damage to another boat that was docked in the area. Officials say the cause of the fire is unknown at this time. The boat that exploded was put on a trailer where it will be examined by the Osage Beach Fire Marshall. The four people that were injured refused treatment at the scene.