Michigan Technical Academy in Detroit closed its doors. Teachers who had worked there on contract just learned that they would not be paid, because the school has other debts.

Teachers at the Michigan Technical Academy had contracts that required the school to pay them through the summer for work they did during the school year. But the school’s management company, Matchbook Learning, alerted teachers in an email Wednesday that the money would instead go to pay off the school’s debts.

Tough luck for teachers who counted on that income to pay their debts, feed their children, meet the mortgage or rent payment.

That’s why unions were created.