Emergency responders searched through splintered wreckage Monday after a line of tornadoes battered several small communities in Texas and Arkansas, killing at least five people. Two of the dead were a young couple who died trying to shield their 18-month-old daughter when a tornado struck their mobile home in Nashville, Ark. Their daughter survived. In neighboring Texas, a tornado pummeled the small city of Van, damaging or destroying 50 to 100 homes and the local schools, a local official said. Farther north, in Lake City, Iowa, a suspected tornado tore the roof from a high school as about 150 students, family and faculty attended an awards ceremony inside Sunday night. All in all, preliminary reports indicated 20 to 25 tornadoes formed Sunday in South Dakota, Iowa, Oklahoma and Texas, according to meteorologist Greg Carbin of the Storm Prediction Center.