A man has died in hospital after an explosion at a building site in north London.
Emergency services were scrambled to the site in Highgate just after 2pm after nearby residents reported their floorboards "shaking" from the blast.
An air ambulance rushed a man in his 50s to an east London hospital where he was later confirmed to have died.
A police cordon was put in place around the building site in Swain's Lane, near Highgate Cemetery.
A professional pianist who lives opposite the site told the Camden New Journal she was practising 'La Passionara' when the blast shook her floorboards.
She told the newspaper: "It made my floorboards completely vibrate. It was terribly loud, a huge huge explosion.
"All the shop keepers came rushing out to see if they could help and the police and ambulance were here immediately.”
Sian Berry, a Highgate councillor and Green Party member of the London Assembly, tweeted: "Really bad #Highgate news - BBC says someone very badly injured in this incident. Most likely a construction worker. Hoping for the best."
High-end property development firm Noble Homes began work on the site around a month ago, with the old terrace due to be replaced by 12 houses and eight retail units.
The Islington-based firm reportedly purchased the shopping parade from the Earl of Listowel in 2016, whose family had owned it for eight decades.
Highgate resident Kenneth Tharp told the Standard he heard the blast from Hampstead Heath.
He said: "I was finishing a tennis lesson on the heath nearby and it stopped us in our tracks. It was a very loud bang."
"The rebuilding has attracted a lot of attention and work had just started recently."
A Met Police spokesman said: "Police were called by the London Ambulance Service at 14:11hrs on Thursday, 16 March to reports of an explosion at an address in Swains Lane, N6.
"London’s Air Ambulance attended and has taken a man to an east London hospital with life-threatening injuries.
"The area is cordoned off and officers remain on scene."
A London Fire Brigade spokeswoman said two fire engines attended the "industrial incident" after being called out just after 2pm.
The Standard has contacted Noble Homes for comment.