There was a “chemical reaction” at the London 2012 Aquatics Center today, which resulted in the release of toxic gas that left victims gasping for air and forced residents to keep their windows and doors closed.

A total of more than 200 individuals have been removed from the Olympic Park, including those who were exposed to the poisonous gas while inhaling it in the nearby sports stadium, companies and construction sites.

Chlorine gas leaked into the Aquatics Centre at the Olympic Park in London owing to a “chemical reaction,” according to the London Fire Brigade. When the pool chemicals were delivered to the Aquatics Center’s plant room, the accident occurred, according to the facility.

A blue truck with hydrochloric acid tanks abandoned outside the location soon after the tragedy was captured in photos from the scene. Because of the potential for chlorine gas leakage when hydrochloric acid and pool chlorine are kept together or combined in any way, experts suggest that these two chemicals never be stored together or mixed at any time for safety reasons.

As a devastating weapon of war, chlorine gas may be fatal if it is inhaled by the human body. Shortness of breath, hazy vision, searing sensation in the eyes, nose, and throat, as well as blisters on the skin, are all symptoms of this disease.

Residents near West Ham United’s famed London Stadium should stay away from the Aquatics Centre while it is being ventilated. Mayor Sadiq Khan has issued an advisory.

“Due to a chemical reaction a high quantity of chlorine gas was released. London Ambulance Service are treating a number of patients”, a Fire Brigade spokesman said. 

He added: “Around 200 people were evacuated from the centre. While we ventilate the premises we would ask those residents in the immediate vicinity to close doors and windows”.

The Olympic Park in east London was alerted by the London Ambulance Service shortly before 10 a.m. that a noxious substance had poured into the building that housed the diving area and the swimming pool.

The fumes were causing many to have headaches and difficulty breathing. A few seemed to be in a fetal position, face down on the roadside.

Queen Elizabeth Olympic Park’s spokesman tweeted:  “There has been an incident @AquaticsCentre this morning involving the release of a gas.

“The area has been cordoned off and evacuated. We’re working with emergency services on site. There are a number of casualties with breathing difficulties being treated by @Ldn_Ambulance”.

There were more than 20 ambulances and 3 fire engines parked outside the closed-off structure, which was being assisted by the police. Helicopter footage showed paramedics treating patients in the parking lot below.

Around 10 a.m., police in Stratford, East London, evacuated the swimming pool and surrounding neighborhood.

A Scotland Yard spokesman said: “Officers were alerted by London Fire Brigade at 9.53am on Wednesday to a leak of noxious fumes at the Aquatics Centre, Queen Elizabeth Park, E20.

“Officers and London Ambulance Service have also attended the scene. A number of people have been evacuated from the premises.”

Numerous London Ambulance Service personnel were sent to the scene.

A spokesman tweeted: “We are responding to an incident at Queen Elizabeth Olympic Park and have a number of resources on scene.”

The site was surrounded by police cars, ambulances, and fire trucks, as shown in photos.

Sadiq Khan, the mayor of London, advised residents to stay away from the affected area while he spoke with emergency services.

He wrote on Twitter: “I remain in close contact with our emergency services who are dealing with a gas-related incident at the London Aquatics Centre this morning.

“A number of people are being treated by @Ldn-Ambulance. Please avoid the area which has been cordoned off and evacuated.”