Dozens of visitors to a Houston-area Six Flags water park ended up suffering from minor skin irritation and breathing problems following a chemical leak on Saturday. 

According to the Harris County Fire Marshal’s Office, 31 were transported to the hospital. More than 50 others were affected but declined to go to the hospital after being decontaminated. 

The incident happened at a single attraction, reported to be a kiddie pool, at Six Flags Hurricane Harbor Splashtown, with the chemicals involved thought to be a combo of bleach and sulfuric acid. 

A visitor who spoke to KHOU says she was with her children at the pool when they started to feel a “burning sensation.” On the way out of the park she added that her kids “seem to be okay.” 

“Most of the patients that we saw during the time in the beginning were all respiratory distress, a little hard to breathe, things of that sort,” said a local fire department chief at a Saturday press conference. “We didn’t see anyone with chemical burns, anything like that.” 

However, a 3-year-old child had issues considered serious enough to be rushed to a hospital. That child is now in stable condition, according to CBS. 

The park also put out a statement.

“At approximately 2:30 [Saturday] afternoon, a small number of guests in a section of the park reported feeling ill with respiratory irritation,” read part of that statement. “The safety of our guests and team members is always our highest priority and the park was immediately cleared as we try to determine a cause.”