Cities built their safety nets on federal money. Now it’s leaving all at once.

When major events unfold in the Twin Cities, a parallel version often plays out at the Hennepin County Medical Center.

The sprawling facility in downtown Minneapolis spanning six city blocks is the area’s largest safety-net hospital and busiest provider of critical trauma care. HCMC is where measles outbreaks, COVID-19 surges, low-income patients and mass casualty events like last year’s Annunciation school shooting merge, said Jeremy Olson-Ehlert, a 13-year veteran nurse and member of the nurse’s union.

The hospital is so busy on some days, nurses have to shuffle patients in what he described as a “musical beds” arrangement.

“A lot of the issues stem from: People can’t afford healthcare. So where do they go? They go to us,” Olson-Ehlert says.

But despite the demand for services, HCMC has been gripped by fears of aggressive downsizing, or even outright closure. The hospital’s cos...