At least 42 American school children have been hospitalized in the US state of Michigan?after falling sick.
The incident happened on Wednesday?at class in an elementary school in Macomb Township in the southeastern part of the state, according to authorities.
Centennial Elementary school was evacuated and rescue workers were at the scene helping students aged 9 to 12 get onto ambulances to leave the school.
MedStar ambulance director of operations Scott Hicks told local media that possibly more students will be hospitalized due to their complications.
According to Hicks,?authorities are at the scene trying to figure out what caused so many children to be sick all of the sudden.
A fog machine that was being used by the school for an up-and-coming school function is believed to have caused the students to be sick.
So far, all of those who were transported to a hospital have not shown signs of ?life threatening injuries,? Hicks said.
Initial reports from doctors say that the kids were showing signs of upper respiratory irritation.
Superintendent Christine Johns of the school district where the elementary school is governed by said several dozen students were taken to the hospital as a precaution.
?Several ambulances responded. The students were transported just for safety precautions. They were all evaluated inside the school, and then we just took them to the hospital for precautionary purposes, she reported.
?It does not appear that any student is seriously ill,? she added.
Macomb Township Fire Chief Robert Phillips said that five students were actually passed out before the rescue crews came in.
Phillips also mentioned the fog machine smoke was being run with dry ice, ?is an abnormal method to operate a fog machine.?
The elementary school was closed down and will not operate for the rest of Wednesday which was a full class day.