UPDATED Monday, June 2, 2014 --- 12:43 p.m.
Students returned to Riverdale High School in Muscoda Monday after several students fell ill Friday.
All the students that fell ill Friday were among the students to return.
What caused them to become ill has yet to be determined. More testing is underway.
Most of the students that got sick were in one of two science rooms. Their symptoms were similar to people who would come in contact with a pesticide, but there are not any farm fields that close to the school.
School officials say they are working to find answers in order to give everyone peace of mind.
UPDATED Friday, May 30, 2014 -- 10:00 p.m.
It was something Riverdale High School has never seen before.
District administrator Bryce Bird said "somewhere in the neighborhood of 15 students were transferred for medical care."
Bird said the situation first developed shortly before noon Friday, with students experiencing multiple symptoms like stomach pain, dizziness, nausea, sweating, confusion and a head ache.
School officials didn't hesitate to evacuate the school.
"We need to find out what it was," Bird said.
Firefighters searched for carbon monoxide traces and an energy company looked for gas -- both without any results.
One clue may be the similarity to two certain types of classrooms the sick students were in; one a biology and the other a chemistry room.
"It seems that it was narrowed down to being in one of those particular classrooms," Bird explained.
Sophomore Isaiah Snyder didn't experience any symptoms himself, but said his friend was acting strange.
"She was acting a little weird so we walked her to the office," he explained, adding that "she had to go to the hospital".
Isaiah is left worried.
"It's scary that something could have happened to them but... I mean I hope that my friend doesn't get seriously injured."
There is one week of school left in Muscoda before summer break, but the district administrator says he isn't sure if the building will be safe to start on Monday.
The sick kids were taken to one of two area hospitals, either in Boscobel or in Richland Center.
UPDATED Friday, May 30, 2014 --- 3:45 p.m.
Authorities are investigating after about 15 students became ill Friday at Riverdale High School in Muscoda.
The District Administrator says the school was evacuated as a precaution while they investigated what was making the kids sick.
The students suffered from symptoms such as headache, stomach ache and dizziness.
About 150 students were in the school today. No staff members were affected by the illness.
The utility company determined there was no gas leak. The fire department found no carbon monoxide problems.
Officials don't know the cause of the illnesses. They haven't ruled out the possibility that it's food related. They do say all the sick students were from two classrooms. Both of the them are science classrooms.
Posted Friday, May 30, 2014 --- 2:30 p.m.
Muscoda Police say there is a possible gas leak at Riverdale High School, and some students have gotten sick.
The Fire Department says the school has been evacuated.
We have a crew headed to the scene and will bring you more information as soon as possible.