A popular swimming pool shut down Monday over concerns of a mystery illness left a number of kids sick.

"He just vomited all over the restaurant and was complaining of really bad like cramps on his side and then he was sick all through the night," parent Kimberly Somers told Denver7 of her son, Brecken, noting that he is now finally feeling better.

Brecken is just one of an undisclosed number of kids who got sick after swimming in the same popular Highlands Ranch pool. Kimberly and other moms made the swimming pool connection over the weekend after other kids experienced similar symptoms.

Denver7 reached out to the Tri-County Health Department - they wouldn't say exactly how many kids got sick, nor would they say what might be causing the illness. They did say, however, there isn't any direct evidence that something in the water is causing the sickness.

For now, the pool is closed while the water is being treated with "heavy amounts" of chlorine. Both the water and sick children are being tested to help determine what is causing the illness.