Employees at a Bronx health care center say failed negotiations forced them to abandon patients and strike Tuesday.

Promesa workers decided to strike for a second time, this time indefinitely, after talks broke down over pensions. Union 1199 leaders want Promesa to provide a more stable retirement plan other than the 401(k), which depends on the markets.

Promesa CEO Ruben Medina issued a statement saying, "We stand by our 401(k) plan. It is fair, competitive and comparable to 1199's plan ... We call on 1199 to do the right thing and come back to the negotiating table."

Patients at Promesa, which treats people with AIDS and addictions, say they've already noticed a difference in the quality of care. "It was slower, not like regular days here," said Gerald Perez.

Union leaders say they gave the center adequate notice about the strike so it could hire temporary workers.