Six Flags Texas water park evacuated after chemical spill sends dozens to the hospital

A chemical leak at a water park in Texas sent dozens of people to the hospital, according to officials.

The incident began around 2:30 p.m. Saturday in a children's pool at Six Flags Hurricane Harbor Splashtown in Spring, Texas, when a lifeguard and several guests started to get sick, Harris County Judge Lina Hidalgo told reporters.

Children and their parents were experiencing "respiratory issues," and 28 of them were transported to hospitals, the Harris County Fire Marshal's office said.

After evacuating the park and conducting preliminary tests of the air and water, investigators found the water had a chemical combination of 35% sulfuric acid and 10-13% bleach, Scott Seifert, the chief of Spring Texas Fire, told reporters. The chemicals are commonly used to clean and treat swimming pools.

Over 65 people were contaminated by the substance, however, no one suffered any chemical burns, according to the fire marshall's office. The affected persons were decontaminated.

The most serious case involved a 3-year-old child, and as of Sunday, that child was stable at Texas Children's Hospital, according to Hidalgo.

"Everybody else was in the less urgent position," she said. "Most people were feeling better afterward."

Representatives from the park said in a statement Sunday night that preliminary findings indicated "there was a vapor release in a small outdoor section of the park that quickly dissipated."

Jeff Filicko, a Six Flags spokesman, said Hurricane Harbor Splashtown would be closed for at least two days to investigate the incident.

"We are working hand in hand with Harris County Public Health officials, along with third party industry experts, to determine a cause, and we will reopen when we are confident it is safe to do so," he said in a statement.

The fire marshal said the last time the park had its fire and safety inspection was June 29 and the Harris County health department conducted health and safety inspections for commercial pools in April.

Hidalgo said that the park is supposed to have systems in place that track the pH level in the water and alert crews quickly, however, she reiterated that the city will make sure this doesn't happen again.

"If you can have 60-plus people get sick, and your system doesn't catch it ... then clearly something is wrong with the system," she said.

ABC News' Timmy Truong and Alyssa Pone contributed to this report.