Sixty-nine people, many of them children, became ill after inhaling potentially fatal chlorine gas at a swimming pool in western Germany, local authorities said Friday, according to AFP. Of those exposed to the gas at the Essen city swimming pool late on Thursday, 47 were admitted to hospitals, including some 40 children, a police spokesman said. Around 90 firefighters, 20 police officers, five doctors and a rescue services helicopter were sent to the scene when the problem was discovered at about 7 p.m. local time. Pool personnel were alerted when those who inhaled the gas, aged from two to 75, began complaining about respiratory problems and sore eyes. Given the warm weather, several people were at the pool at the time. An investigation has been launched into the accident.