More than 15,000 Minnesota nurses walked off the job Monday at 16 different hospitals in Twin Cities and Duluth in what is being called the largest private-sector nurses strike in the country, according to the Minnesota Nurses Association.

The three-day walkout comes after months of failed negotiations over staffing, retention and pay. The union nurses are asking for a 30% pay raise over three years. The hospitals have countered with a 10% to 12% increase.

While the two sides remain far apart, striking nurses argue a significant pay increase is vital to retain caretakers as hospitals remain chronically understaffed since the COVID-19 pandemic. They say staff shortages are not safe for nurses or patients.

“I can’t give my patients the care they deserve,” said one nurse.

“Staffing has been the real roadblock for the nurses,” said Sam Fettig, spokesman for the union. “Hospitals have not offered a substantive counter proposal at all.”

“We want assurances in our contract that if a nurse says their assignment is unsafe that we are not disciplined,” nurse union president Mary Turner said. “We have had nurses that have been sent home for refusing an unsafe assignment.”

Nurses are also seeking more paid sick leave and parental leave.

Nurses in Twin Cities have been working without a contract since the end of May, while the union said the contract for Twin Ports nurses expired at the end of June.

Hospitals have brought in thousands of traveling nurses during the strike to minimize disruptions to patient care. Elective surgeries have also been rescheduled.

Nurses at Twin Cities’ two largest adult trauma centers, Hennepin Healthcare and Regions Hospital, are not participating in the walkout, which is set to end Thursday morning.

In the latest round of talks Saturday, hospital management walked away from the negotiating table. No new talks are scheduled.

Minnesota’s strike comes after about 8,000 nurses, represented by the California Nurses Association, went on a one-day strike in April to call attention to concerns over staffing shortages and personal protective equipment as COVID-19 nears an endemic stage in the U.S.