DES MOINES, Iowa (AP) — The Des Moines school district has sued the state, challenging a policy that forces districts to hold at least half of their educational programs in-person in classrooms unless their areas meet a high threshold of positive coronavirus cases. The lawsuit filed Tuesday by Iowa’s largest school district asks the court to reverse the state’s rejection of its plan to begin the school year with students at home and to prevent the state from forcing it to reopen schools “when it is unsafe to do so.” The court filing comes as the Ames school district announced Tuesday it would take similar legal action. Last week, the Iowa State Education Association and the Iowa City school district sued.