A two-year-old boy has died after a wall collapsed and fell on top of him.
The boy was walking along Southampton Road in Kentish Town, north London, with his childminder at about 1315 GMT when the 6.5m (21ft) wall collapsed.
He was taken to hospital by the London Ambulance Service with a serious head injury but pronounced dead at 1445 GMT.
Scotland Yard said a joint investigation has been launched between the police and the Health and Safety Executive.
The childminder was also taken to hospital, but her injuries are not thought to be serious. No-one else was hurt in the accident.
Police have said they cannot confirm Thursday's gale-force winds were to blame for the tragedy but that the weather "would not have helped".
Police said they know the youngster's identity but are awaiting formal identification.
Camden Council said in a statement that the death of the two-year-old boy was "deeply concerning".
It added: "As is normal process following a death of this kind, police and the Health and Safety Executive are now investigating and we will also carry out our own investigation.
"Our building control team has secured the site with police."
A post-mortem examination is due to be arranged shortly.