Chopper 7 was over Fort Dearborn Elementary School, located at 9025 S. Throop St. in Chicago's Brainerd neighborhood, about 2 p.m. There were a number of Chicago fire trucks and ambulances on the scene.
Officials said the 11 students were in good condition.
SEE ALSO: Golfer, 70, hit by vehicle driving on NW Side course, officials say
Sources said they may have eaten "something" before they were taken to hospitals.
Parents at dismissal Tuesday said the incident took place inside a sixth-grade class, allegedly, after a student brought cookies to school that were unknowingly laced with THC.
"That's not cool. It's not. Check your kids' book bags," parent Sharelle Russell said. "Why ain't nobody checking to see if these kids, why are they giving out cookies or any candy? Like, come on, they shouldn't be passing it out anyway."
One parent said her godson nearly ate one of the cookies.
"He just said he tasted the cookie, and it didn't taste right. So, he spit it out, and that was it. I don't think it was packaged or anything," parent Trianna Jones said.
Chicago Public Schools did not immediately respond to a request for comment.
Chicago fire officials say the students are expected to be OK.
The school's principal said in a letter to parents:
"Safety is always my top priority, which is why I am writing to notify you of a situation impacting our school. Earlier today, we were made aware that a few members of our school community had ingested an unknown substance. We immediately provided support to our impacted community members and notified their parents and the CPS Office of Safety and Security. While I cannot provide further details for privacy reasons, I can share that we are handling this matter in accordance with CPS policies.
"We believe our community member may have ingested the unknown substance in the form of 'edibles,' which are food or drinks that are made with cannabis or other prohibited substances. Prohibited substances of any kind are not allowed at our school, and we encourage you to take this opportunity to have a conversation with your child about the health risks associated with consuming edibles, and to remind them not to accept food if they do not know where it came from.
"Thank you for your partnership as we continue striving to create a healthy and positive learning environment at our school."