A strike by 28,000 Chicago teachers was narrowly averted Monday evening when the Chicago Teachers Union reached a tentative agreement with the school district only minutes before their midnight deadline.  With the strike off, classes are continuing as usual Tuesday morning.  Financed by 88 million dollars of surplus funds from the city’s Tax Increment Financing district, the agreement includes cost-of-living increases in the last two years of the four-year contract and maintains teacher pay increases associated with seniority and experience.  While saying there are still issues that need to be addressed in Chicago schools, CTU President Karen Lewis indicated commitments from the Board of Education that would improve classrooms, addressing class sizes and rules on teacher layoffs and re-hiring.  The tentative contract must still be ratified by the union’s House of Delegates and approved by its full membership.