A search is under way for anyone trapped in a four-storey building which collapsed in east London.
Cordons will remain in place on Wednesday: pic by BBC News website user Florian Bohl
Emergency services were called to Commercial Road, Whitechapel, on Tuesday afternoon after reports of a building partially collapsing.
Sound tests are being carried out on the building to determine whether anyone is trapped inside.
Paramedics at the scene treated 10 adults and one boy for shock, but no-one was taken to hospital.
Steve Ware, from the London Fire Brigade, said: "We're trying to work out if there are people inside. We have no confirmation of anybody involved at the moment.
"We have specialist teams actually in the process of using listening devices and we're considering what plan to adapt."
The building was being refurbished when the first and second floors collapsed, causing up to eight metres of debris to fall onto the pavement.
It was too early to say what had caused the collapse, said the brigade.
Part of the building fell against scaffolding on the front of the site, which is leaning against a lamp-post.
Eyewitness Ali Morris, landlady of The Castle Pub, said: "My flatmate came and told me he'd heard a loud bang so we looked out of the window and the fire brigade were already coming out.
"We came down, they sealed the road off and you could see all the debris that had come out of the building and the scaffolding is leaning right over."
Commercial Road was blocked in both directions and traffic was diverted along Whitechapel Road towards Mile End.
The incident also affected buses, with diversions places on routes 15 and 155.
Scotland Yard said cordons around the collapsed building were expected to remain in place until further notice, and police advised motorists to avoid the area around the western end of Commercial Road.