Madill, OK (KOCO/CNN) - Students and staff at an Oklahoma elementary school were sent home Wednesday after dozens fell ill.
The school was evacuated after many became nauseous and dizzy.
Classes were later canceled for the day.
School officials say they checked for a possible gas or carbon monoxide leak, but found nothing.
The school will remain closed Thursday so health officials can investigate and the building can be disinfected.
KOCO/CNN