The London Aquatic Centre in Stratford remained closed on Thursday after a large quantity of chlorine gas was released sparking a mass evacuation.
Around 200 swimmers and staff members at the Olympic Pool were evacuated with 50 people treated in hospital for breathing difficulties, according to the BBC.
Homerton Hospital in east London said it had admitted 13 adults and five children with respiratory problems. They added two people were kept in overnight as a precaution.
A spokesperson for Barts Health NHS Trust said: “We are treating patients at Newham Hospital and The Royal London Hospital who were evacuated from the Queen Elizabeth Park Aquatics Centre following an incident.”
The London Legacy Development Corporation (LLDC) has confirmed the park has since been reopened but the former Olympic venue remains shut.
The gas release occurred when the facilities management company which operates the plant room took a delivery of pool chemicals.
London Fire Brigade said they had used fans to disperse the build up of gas.
One person was treated on a paramedic’s gurney while multiple swimmers, still in their trunks and goggles, were given foil blankets to keep them warm.
Workers nearby told how they heard a fire alarm going off at around 9.45am on Wednesday with people fleeing the Stratford venue covering their mouths and some suffering coughing fits.
A builder told The Standard he saw a group of children emerge from the Olympic swimming pool and around eight elderly people being covered in foil blankets by paramedics.
He said: “The children looked ok but the group of elderly people looked worse off.”
Another passerby said he could “sense a strong smell of chlorine” as he jogged past the venue in Stratford.
A London Fire Brigade spokesperson said: “Due to a chemical reaction a high quantity of chlorine gas was released. London Ambulance Service treated a number of patients. Around 200 people were evacuated from the centre.
“Fire crews used fans to ventilate the premises. Once low levels were reported on our detection equipment we handed the centre back to the building owners.”
