You may have seen a commotion at the Texas State Aquarium around 3 p.m. Thursday, but don't worry -- it was just a drill.

The Aquarium hosted a joint emergency drill with the Corpus Christi Fire Department and other first responders at their Wild Flight Theater. Organizers said they have been working with the CCFD for years to plan their coordinated response to a hurricane, diving accident, injury or other emergency incident.

Officials warned that several CCFD and state emergency vehicles would be in the bus turnaround near the Aquarium’s small parking lot, and that the CCFD's HAZMAT unit and state response agency would also be there. That's because they were training on what to do in case of a chemical release at the Aquarium.

In this case, the chemical in question was chlorine.

"We did it in real time," said Battalion Chief Tony Perez of the Corpus Christi Fire Department. "We had our units respond just like they would. We have our hazard, and what you are seeing here is 'decon' setup, and we are going to mediate the hazard."

Guests were still allowed into the Aquarium during the drill. They were alerted as to what was going on so they wouldn't be alarmed.