Excerpts from abc7chicago.com:
The Lincolnshire Police Department said officers responded to a community pool at 445 Village Green at about 2:20 p.m. for reports of two unresponsive teenagers. When officers arrived, they found the teens unconscious but breathing. They were taken to Lutheran General Hospital in serious condition.
The initial investigation suggested there was a chlorine gas leak or a carbon monoxide leak after servicing the pool earlier in the day. Firefighters and hazardous material teams focused on the clubhouse near the pool where the boy and girl were found. Some of them inhaled the poisonous fumes in the process. A total of 14 people ended up being transported to area hospitals for treatment: six police officers, four firefighters, and four civilians, including the two original victims.
Fire Chief Tom Krueger said two of the devices they use to measure hazardous materials at the pool were broken due to the high levels of poisonous gas in and around the clubhouse and pool. He said in his 19 years on the job he had never seen anything like that before.