As climbing rivers knocked out an Iowa bridge and flooded Illinois farms, communities along the Mississippi River are bracing for what could be its biggest overflow in 15 years, the AP reports. The National Weather Service warned of crests of 10 feet above flood stage and higher over the next 2 weeks. “I've been downtown for 37 years and I have never seen anything like this,” said one Cedar Falls, Iowa, resident. (More Mississippi River stories.)