A man has died after being hit by a sign which fell from a William Hill betting shop.
The man, believed to be in his 20s, died following the incident in Camden, north London, at 4.55pm, Scotland Yard said. He was treated at the scene in Camden Road for a head injury and transferred to hospital where he later died, London Ambulance Service (LAS) said.
"Every effort was made to resuscitate him at the scene and on the way to University College hospital," an LAS spokeswoman said.
The sign was made of metal and measured about 30ft (9 metres) across, covering the length of the shopfront.
Police erected a forensic tent on the pavement to cover the place where the man was killed, and cordoned off the surrounding area.
A William Hill spokeswoman said: "There is an urgent investigation under way and we are still establishing facts and liaising with authorities.
"As such, we don't have a comment to make at this time."
Ioana Nita, 21, was working at a nearby restaurant when the accident happened. She said: "I'm shocked. We heard a very loud noise. Me and a colleague went outside and saw the guy lying on the floor.
"Five guys picked up the sign and it was put on the side. His hands were covered in blood and he wasn't moving.
"Lots of people were in a circle around him, then the ambulance arrived and they were trying to get him back to life, pressing on his heart."
She added: "I just want to go home and cry. I don't know how that can happen. The sign is huge. Everyone said he was just walking past the shop. I cross that way five times a day. That could have been me."
A Scotland Yard spokesman said: "Officers and London Ambulance Service attended and the man, believed to be aged in his 20s, was taken to a central London hospital for treatment. He died there a short while later.
"At this early stage it appears the man received his injuries after being struck by a sign or board which has fallen from a building."