DES MOINES, Iowa (AP) — The Des Moines School board on Monday night 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, Iowa’s largest district with more than 33,000 students, 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 Department of Education has threatened to deem the district not in compliance, potentially forcing it to extend its school year at a cost of about $1.5 million a day. The board has argued a high prevalence of the coronavirus statewide and in Polk County makes it unsafe to hold in-person classes.

The board agreed on a 6 to 1 vote to gradually start a hybrid plan of in-person and online courses, starting with pre-kindergarten on Oct. 12 and ending with high school on Nov. 10.

However, the board asked Superintendent Tom Ahart to work with local public health experts on metrics that would trigger a return to online-only classes. Ahart had suggested metrics including an infection rate of 5%, but since Polk County’s rate has hovered at 7% or higher in recent weeks, that would mean classes would remain online.

The board will meet Sept. 28 to set metrics that would trigger the shift of students to online-only instruction.