Flooding rivers across Iowa forced more residents to evacuate on Thursday, with at least 10,000 people fleeing in Cedar Rapids as the rising Cedar River burst its banks. Rescuers had to use boats to rescue many of the stranded residents of the city. The National Weather Service in Iowa indicates that the flood has reached historical proportions and could get worse. The power has gone off for much of Cedar Rapids and communication was difficult. Residents of several communities around the state have been using sandbags for days to stop the flow of water from reaching their communities. Some forecasters believe flooding of this nature is unlikely to occur more than once in several hundred years. Another problem is that corn prices hit a record high again Thursday and the short-term outlook did not look good as heavy rainfall continues to flood fields and ruin crops.