Around 300 people were forced to evacuate New Zealand's Olympics hospitality house after a fire on Wednesday evening.
Police, fire and ambulance serivces were called to the Kiwi House pop-up venue near King's Cross station in central London after two gas canisters fuelling a barbecue exploded.
The blast happened just metres from the platforms used by high-speed Javelin trains to shuttle visitors to and from the Olympic Park.
Brook Johnstone, 55, from Port Waikato, New Zealand, said: "I looked around and the gas bottle had a little flame around it.
"The cook was trying to put it out and the flame just got bigger so I just said 'Let's get out of here'.
"We got inside and everyone was evacuated."
Mr Johnstone said the canister exploded with such force that it blew the roof off the barbecue area.
Fortunately, no one was injured in the explosion or fire.