Nearly every public school in Detroit was shut down on Monday as teachers city-wide held a "sickout" over news that the embattled district would not be able to pay them past June 30.

The protest kept 94 out of 97 schools closed after the Detroit Federation of Teachers (DFT) announced the action on Sunday. Detroit Public Schools (DPS) emergency manager Judge Steven Rhodes told the union over the weekend that without additional funding from the legislature, the district would not have enough money to pay its 2,600 teachers' already-earned salaries.

Summer school and additional services would also be cancelled, he said.

"There's a basic agreement in America: When you put in a day's work, you'll receive a day's pay. DPS is breaking that deal," said DFT interim president Ivy Bailey. "Teachers want to be in the classroom giving children a chance to learn and reach their potential. Unfortunately, by refusing to guarantee that we will be paid for our work, DPS is effectively locking our members out of the classrooms."

The school system's total debt is more than $3 billion. Rhodes warned state lawmakers in early March that the district was rapidly running out of money and would be broke on April 8. In response, the state Senate approved $715 million in funding, which the House is currently debating.

"Teachers in Detroit have sacrificed greatly to ensure our schools stay open and our kids have the opportunity to learn," Bailey said. "But working without pay is the straw that breaks the camel's back. Teachers have mortgage payments, utility bills, grocery bills. Being paid for their work isn't a luxury, it’s a necessity."

Monday's sick-out—staged as such because it is illegal for teachers to strike under Michigan law—is the latest in a series of similar actions. Educators held a sickout in January to protest the district's decrepit infrastructure, which included crumbling school buildings, cockroach and rat infestations, and overwhelmingly large class sizes.

Earlier this year, the Detroit school board filed a federal lawsuit against the state alleging that the Michigan emergency manager law is partially to blame for the financial troubles.