More than 2,200 nurses at the University of Chicago Medical Center are on strike Friday after contract talks broke down yesterday.

Hundreds of nurses participated in a noon-time rally outside the medical center in Hyde Park with many chanting “strike, strike, strike!”

The nurses say they’re striking to force the hospital to address chronic staff shortages.

Joann Allen has been a nurse at the center for 40 years working in the postpartum department, and said she’d rather be working.

“I’m hurt. I couldn’t sleep because I know my mothers and babies need the best care and if they give us the right staffing, we can do it,” she said.

Delilah Flexas works as a critical care nurse in the pediatric unit at the center’s Comer Children’s Hospital.

“It’s extremely hard. This is not what we went into nursing to be outside the doors. We want to be inside with our patients,” she said.

The nurses are represented by the National Nurses United Organizing Committee and National Nurses United.

Union leaders contend chronic short staffing across the hospital is putting patient safety at risk.

“We have offered the hospital a staffing proposal that would allow us to provide the highest quality of care to our patients, but management not only rejected our proposal, but failed to offer a counterproposal,” said Johnny Webb, a registered nurse.

“We hope this strike sends a clear message to UCMC: We are not backing down and we will continue to fight and advocate for our patients.”

The union claims nurses are being forced to work overtime after they have already completed their 12-hour shifts. Nurses note that various studies show that when nurses are not adequately rested they are more apt to make errors in patient care.

Medical center president Sharon O’Keefe said the strike presents a significant challenge but it’s prepared to continue operating.

“We are disheartened that we had to get to this point,” O’Keefe said. “We heard from the union that staffing was a key issue. We offered a staffing proposal that included the addition of more than 30 new full-time positions.”

O’Keefe said contract negotiations broke down over the issue of incentive pay.

“The union ended negotiations,” she said.

“We are prepared to continue operations and care of our patients in need of our services.”

Michael Puente covers Chicago and Northwest Indiana for WBEZ. Follow him on Twitter @MikePuenteNews.