A fierce line of severe weather hit the central and south-central United States late Sunday, killing at least 16 people in Arkansas, one in Oklahoma, and one in Iowa. Some of the worst damage was north of Little Rock, Arkansas, where reported tornadoes devastated the towns of Mayflower and Vilonia. "It's chaos here," said Vilonia Mayor James Firestone. "Our downtown area seems like it's completely leveled." In Mayflower, about 30 kilometers to the southwest, authorities closed a section of a highway after a tornado "as much as a half-mile wide" roared through the area, the National Weather Service (NWS) said. CNN estimated the winds from the storm at 210 to 240 kilometers per hour (kph) in Mayflower. Ten deaths were reported in Faulkner County, where Vilonia and Mayflower are located, the Arkansas Department of Emergency Management said, also confirming five deaths in Pulaski County and one in White County. More than 100 people were treated at hospitals in the state, the agency said. NWS meteorologist Jeff Hood said that at least one long-tracked tornado began in Pulaski County, northwest of Little Rock, and moved northeast from there. The agency will survey damage in coming days to determine the rating of the tornado and if any other tornadoes hit in the region, he said. President Barack Obama offered his condolences to storm victims while on a four-country tour of Asia, pledging that federal assistance would arrive shortly. "I want you all to know FEMA (Federal Emergency Management Agency) is on the ground and will help Americans in need, and your country will be there to help and rebuild as long as it takes," Obama said from the Philippines.