GRAYSLAKE, Ill. (CBS) — Three popular high school wrestling coaches who led their teams to state finals have abruptly resigned.

The northwest suburban coaches were under investigation for their behavior at a state wrestling meet, but school officials are not explaining what happened, CBS 2’s Pamela Jones reports.

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 “Maybe there was some type of mistake by the coaches but nothing that they should lose their jobs over,” says parent Dena Hein.

She’s the proud mother of a Grayslake North High School wrestler who competed in state finals last month.

But some parents and students have been wondering what may have happened during the competition that pushed three coaches to resign.

School board members accepted the resignations of Grayslake North coaches Tom Frye, Erik Jensen and John Glorioso without saying why.

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Parents say all the wrestling coaches have been committed to the safety and education of their kids. And they think next year’s students should benefit from their instruction.

Jack Curtis also has a son who wrestles for Grayslake Central. His son wasn’t wrestling at the meet in question, but he says the athlete has done well under the coaches’ guidance.

“We don’t really know what happened. It’s not important that we do. But I felt it important that all of the good things were pointed out as well,” Curtis said.

District 127’s superintendent said in a statement that policy prohibits comment on confidential personnel matters. The district says Tom Frye’s resignation is effective immediately.

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The other two coaches’ resignations will be effective at the end of the school year.