Nurses at two of New York City’s largest hospitals walked off the job in a dispute over pay and staffing levels after a weekend of negotiations failed to produce deals for new contracts, with talks falling apart overnight, CBS New York reported.

The walkouts began at 6 a.m. and involve as many as 3,600 nurses at Mount Sinai Hospital in Manhattan and 3,500 at Montefiore Medical Center in the Bronx.

The New York State Nurses Association, which represents the workers, said it was being forced into the drastic step because of chronic understaffing that leaves nurses caring for too many patients.

“Nurses don’t want to strike. Bosses have pushed us to strike by refusing to seriously consider our proposals to address the desperate crisis of unsafe staffing that harms our patients”, - the union said in a statement.

At around the time the strikes began, the union tweeted a message saying, “To all of our patients, to all New Yorkers, we want to be absolutely clear: If you are sick, please do not delay getting medical care, regardless of whether we are on strike. In fact, we invite you to come join us on the strike line after you’ve gotten the care you need, adding that seeking care wouldn’t constitute crossing the picket lines”.