A boat fire and explosion that injured seven people Sunday in northwest Iowa’s East Okoboji Lake is under investigation by the Iowa Department of Natural Resources. Six adults and one child were hurt in the incident though none of their names have been released. The 35-foot cabin cruiser was stopped at a gas dock when the blast happened. Two of the people were thrown into the water by the blast and were rescued by a bystander. The DNR’s looking into what caused the fire and explosion.