Mr. Bradley said firefighter units were focused on shifting debris so search and rescue dogs could get in to find those still missing.

WSJ: Tornadoes Blast Oklahoma

Evansdale, Iowa (CNN) -- Scent dogs used by searchers looking for signs of two missing young girls in Iowa ran around a lake and stopped at the water's edge, the mother of one of the girls said.

CNN: Mom: Dogs searching for Iowa girls stopped at edge of lake

Crews had worked late into the night Wednesday at Lilydale Regional Park, washing away soil with fire hoses and bringing in search dogs to look for one of the children who had remained missing overnight.

CNN: 2 children dead after gravel slide at Minnesota park