DES MOINES, Iowa (AP) — The Des Moines School board has set a date for returning to school but put off establishing a coronavirus infection rate that would force the district to revert to online-only instruction. Des Moines schools has been the state’s only school system that has refused Gov. Kim Reynolds’ order that they hold at least half their classes in-person unless they have received a waiver because of high infection rates. The board voted to gradually start a hybrid plan of in-person and online courses, starting with pre-kindergarten on Oct. 12 . However, the board will hear from public health experts on metrics that would trigger a return to online-only classes. The board will meet Sept. 28 to set such metrics.