A crane has collapsed on to two terraced houses in east London leaving residents trapped inside.
The 20m (65ft) crane crashed on to the properties and a block of flats under development in the Gale Street area of Bow, just before 14:40 BST.
The London Fire Brigade (LFB) is working to free people trapped inside. There are no reports of injuries.
A police blockade is in place and motorists are advised to avoid the area.
A video posted on social media showed a terraced house with part of the roof collapsed.
Eyewitness Bridget Teirney said she believed the crane driver had escaped safely.
London Ambulance Service tweeted to say it had “a number of crews and specialist resources” at the scene.
At least three fire crews have been sent to the scene.
LFB Assistant commissioner, Graham Ellis, said securing the house will be a “complex rescue operation”.
Mr Ellis said: “This is a multi-agency response and is likely to be a protracted incident.
“Our Urban Search and Rescue crews are undertaking a complex rescue operation and using specialist equipment to search the properties.”
The fire service has “deployed a drone to provide aerial imagery to aid with the rescue”.