CRANDON (NBC 26) — Students and staff members are set to return to class in Crandon in early April.
District leaders say they decided to extend the closure of the school through spring break after an unknown illness went through the district last week.
A letter to families said several students and staff experienced shortness of breath, feeling light-headed and high pulse rates.
They eventually discovered it was from high levels of carbon monoxide.
Thirty-nine people were treated, and district leaders are planning to return to class April 2.
