CARPENTERSVILLE – District 300 and its teachers union vehemently disagreed on whether lower class sizes or higher compensation derailed a last-ditch bargaining session Monday that led to the first district labor strike since 1972. Regardless, the union’s decision cancels all classes and other school-sponsored activities during the strike.

District board member Joe Stevens said the district offered to hire 60 new teachers that met the union’s long-sought demand for lower and manageable class sizes at the elementary, middle and high school levels.

But the union, LEAD 300, scoffed at it, asking for higher salary increases in exchange for it, Stevens said.