A lawsuit filed Thursday claims a nonprofit hospital in northwest Chicago failed to provide charity care to two low-income, uninsured patients, reopening a longstanding controversy in Illinois over whether hospitals are doing enough charitable work to qualify for lucrative tax exemptions. Swedish Covenant Hospital gets about $8 million in annual tax breaks and owes the community a more reliable charity care system, the plaintiffs' attorney Alan Alop of the legal services group LAF said at a press conference Thursday in Chicago. The lawsuit claims unfair practices under the Illinois consumer fraud law and seeks $50,000 in punitive damages and a change in hospital policy.