AUSTIN (KXAN) — A total of seven people were taken to the hospital after a chlorine gas leak was reported Monday morning in Horseshoe Bay, the city of Horseshoe Bay told KXAN in a statement. The cause of the leak was due to a truck driver who delivered a chemical to the Central Water Plant and "unintentionally mixed two chemical compounds in a holding tank," the city said around 10 a.m. on social media. This then released the chlorine gas "from the tank vent." The city of Horseshoe Bay said a chlorine gas leak in the area highlighted sent one person to the hospital on Monday, Oct. 21. (Courtesy: city of Horseshoe Bay) "The chemical reaction released chlorine gas from the tank vent, which drifted with the south wind into the local area, causing eye burns and nasal irritation. The tank was shut down within minutes, but the off-gases continued to pose an air exposure issue," the city said in the statement. Seven people, including water plant employees and the truck driver, were all taken to the hospital, the city said. The city said the six employees were released, but the driver stayed "for observation." The Horseshoe Bay Police Department then went door-to-door to warn residents in the area who were affected by the gas leak and told them "to remain indoors until the gas dissipated," the city said. "Emergency response teams acted swiftly, including the City of Horseshoe Bay and Sunrise Beach Fire Department. Following thorough air quality checks, it was confirmed that the area was safe for all activities to resume as usual. There is no further risk to the public, and air quality levels have returned to normal," the city said. Shortly before 3 p.m., the city said the gas leak was "fully contained." "The City of Horseshoe Bay is taking steps to review the chemical delivery process and will investigate the existing protocols to ensure that this does not happen again," the city said. Any residents who have questions or concerns call the Horseshoe Bay Fire Department at (830) 598-6953, the city said.