While teachers in Community Unit District 300 walked the picket line, classes remained in session at Cambridge Lakes Charter School in Pingree Grove.
The charter school belongs to District 300, but its 67 teachers are not in the striking LEAD 300 union, which is why the school was still open.
The Northern Kane Educational Corporation runs the five-year-old school, which is free to students living within the district -- about 830 students attend the kindergarten through 12th-grade school.
Tuesday turned out to be an uneventful day at the school.
School leaders say it's because they got the message out early about being open during a potential strike.
The first notice went out to parents Nov. 16 and on Monday the school reminded parents a strike would not affect the charter school, said Christopher Troska, a school spokesman.
Fewer than 10 parents called the charter school Tuesday to verify it was still open, said Larry Fuhrer, president and chief executive officer of the Northern Kane Education Corporation.
"The calls that have come today would be the normal amount of calls." Fuhrer said.
Charter school students also weren't affected by the busing company that serves the rest of the district.
The buses weren't operating Tuesday during the strike, and while the charter school offers its own busing, most kids either get rides from their parents or walk to school, Troska said.