. -- Severe weather including a tornado that spun across the Oklahoma-Missouri border killed at least 18 people Saturday, mangling buildings and trapping people in rubble in the storm-weary region.
At least six people were killed as the tornado flattened the northeastern Oklahoma town of Picher before the funnel struck across the border about 15 miles away near Seneca. At least 12 were killed in southwestern Missouri, the State Emergency Management Agency said.
"They're going over the hard-hit area and turning over everything and looking," SEMA spokeswoman Susie Stonner said of emergency workers' search for victims. "It's hard to do in the dark."
The tornado in Picher, an economically depressed and pollution-scarred mining town that many residents had already abandoned, caused major damage in a 20-block area.
The death toll in Oklahoma could climb, said state emergency management spokeswoman Michelann Ooten.
"I know they are going through the rubble, trying to find people missing," she said. "There are numerous injuries."
Oklahoma Gov. Brad Henry issued a statement saying a major emergency response was underway. He planned to visit the area today.
"Our thoughts and prayers are with the people of Picher and all of the other Oklahoma communities that have been impacted by the latest wave of severe weather," Henry said.
Other tornadoes were reported in southeastern Oklahoma near McAlester and Haywood in Pittsburg County and in rural Pushmataha County.
Television footage showed some destroyed outbuildings and damaged homes west of McAlester and near Haywood. At a glass plant southwest of McAlester, the storm apparently picked up a trailer and slammed it down onto garbage bins.
In storm-weary Arkansas, a tornado collapsed a home and a business, and there were reports of a few people trapped in buildings, said National Weather Service meteorologist John Robinson.
Central Park Elementary School in the northwest Arkansas city of Bentonville had roof and window damage, and damage was also reported at Pine Creek Center School.
The storms remained active into the evening as they swept east, with watches and warnings abundant across a wide swath of the Plains and South.
Tornadoes killed 13 people in Arkansas on Feb. 5, and seven others were killed in another spate May 2. In between was freezing weather and river flooding.