Sixteen workers were hospitalized on Wednesday morning after "improperly mixed pool chemicals" created a hazardous reaction at the grand opening of Great Wolf Lodge in Texas, officials said.

Webster city officials said in a statement that a third-party contractor caused the leak in an isolated building separate from the newly opened hotel and water park.

"Two subjects that are having breathing difficulties after inhaling some sort of chemical," a dispatcher can be heard in a 911 call obtained by NBC’s "Today."

Webster Fire Chief Dean Spencer said the chemicals improperly mixed in the tank were identified as sodium hypochlorite and sulfuric acid, the Houston Chronicle reported.

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first responders outside great wolf lodge

Officials said 16 workers in the immediate area were hospitalized. (FOX26 Houston KHOU)

Five individuals were able to evacuate the building, while 16 other employees and contractors working in the immediate area were rushed to a nearby hospital after being decontaminated, officials said.

first responders outside great wolf lodge

City officials said a third-party contractor mixed two chemicals in an isolated building, resulting in a hazardous chemical reaction. (FOX26 Houston KHOU)

Fire personnel isolated the tanks and monitored the area, confirming no hazardous chemicals were detected in the hotel or water park.

first responders outside great wolf lodge

No hazardous chemicals were detected in the hotel or water park, officials said. (FOX26 Houston KHOU)

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Great Wolf Lodge thanked first responders for their quick action in a statement obtained by FOX26 Houston and said the water park will open as planned.

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"The health and safety of our guests and pack members is always our priority, and we greatly appreciate the quick actions of first responders from the city of Webster in response to an incident at an external building outside of the main indoor water park and resort caused by an external vendor," the statement said. "We've received the all-clear to open the resort and all water park attractions as planned from the Webster Fire Department."