Dozens of people were taken to hospital with breathing problems today after a bungled delivery to the London 2012 Aquatics Centre today sparked a 'chemical reaction' that led to deadly Chlorine gas being pumped out.
More than 200 people have been evacuated from the sports arena and surrounding businesses and building sites in the capital's Olympic Park in east London with people who breathed in the noxious substance treated in the car park. 29 people were taken to hospital with the site sealed off for five hours.
One person was treated on a paramedic's gurney while multiple swimmers, still in their trunks and goggles, were seen being cared wrapped in foil blankets to keep them warm. Almost 50 people needed treatment at the scene.
London Fire Brigade said a 'high quantity of chlorine gas' was released inside the Aquatics Centre at the Queen Elizabeth Olympic Park in London due to a 'chemical reaction'. The Aquatics Centre said the incident happened 'when the facilities management company that operates the plant room took delivery of pool chemicals'.
Pictures from the scene showed a blue lorry with tanks of hydrochloric acid abandoned outside shortly after the incident. It is not known what happened next, but for safety reasons, experts recommend that hydrochloric acid and pool chlorine should never be stored together - and should absolutely never, ever be mixed, under any circumstances - because they can cause the release of chlorine gas.
Chlorine gas, a substance so deadly it has been used as a weapon of war, can be fatal if breathed in. It also causes shortness of breath, blurred vision, burning pain in the nose, eyes and throat and and blisters on the skin.
London Ambulance Service said 29 people had been taken to hospital following a chlorine gas leak at the Aquatics Centre at London's Queen Elizabeth Olympic Park.
Darren Farmer, London Ambulance Service gold commander, said: "This morning we responded to a major incident at the London Aquatic Centre in Stratford, alongside colleagues from the London Fire Brigade and Metropolitan Police.
"We sent a significant number of resources including 13 ambulance crews, advanced paramedics, two medics in fast response cars, two incident response officers, a medical incident adviser and members of our hazardous area response team (HART).
"We also dispatched medics from London's Air Ambulance. Our crews took 29 patients to hospital and assessed a further 48 patients at the scene. The majority of patients were reporting minor breathing difficulties.
"Thank you to all our teams who responded today, both at the scene and in our control room, and to our firefighter and police colleagues."
LAS said it stood down its response shortly after 3pm. The Aquatics Centre, yards from West Ham United's world famous London Stadium, was ventilated for most of the day and the Mayor of London has urged people to avoid the area.
'Due to a chemical reaction a high quantity of chlorine gas was released. London Ambulance Service are treating a number of patients', a London 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 London Ambulance Service were called the the Olympic Park in east London at just before 10am after a noxious substance leaked into the building containing the swimming pool and diving area.
People described suffering headaches and struggling to breathe because of the fumes. Some were seen lying on their backs on the pavement.
A spokesman for the Queen Elizabeth Olympic Park 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'.
Pictures from the scene showed more than 20 ambulances and three fire engines outside the sealed off building being supported by police. Footage filmed from helicopter showed paramedics treating people in the car park outside.
Police evacuated the swimming pool and cordoned off the surrounding area in Stratford, East London at around 10am.
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.'
The London Ambulance Service sent multiple resources in response to the incident.
A spokesman tweeted: 'We are responding to an incident at Queen Elizabeth Olympic Park and have a number of resources on scene.'Pictures showed multiple police vehicles, ambulances and fire engines parked near the 114-metre slide at ArcelorMittal Orbit.
Mayor of London Sadiq Khan urged Londoners to avoid the area while he liaised 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.'