A man in his 50s died in an explosion at a construction site in north London, police have said. Emergency services, including the London air ambulance, were called to an “industrial incident” in Swain’s Lane, Highgate, just after 14:00 GMT.The site was once a petrol station and part of the demolition work required removing underground tanks. The explosion “sounded like a bomb”, locals said. Roads have reopened but police remain on scene. The 1930s terrace, on the site of a former shopping parade, is due to be replaced by eight new shops and 12 houses. Owners Noble House were aware of safety concerns but had claimed to residents there were “no indications of hazardous materials”.Local resident Kim Gray said the explosion “sounded like car bomb” and shook local buildings. Ozan Yelken, 27, a supervisor at neighbouring Bistro Laz restaurant, said: “I heard a very big bang, like a wall collapsing. “I ran outside and it was very quiet for a few seconds then people started running into the construction site.” Mr Yelken said he saw workers removing a petrol tank earlier today. The Health and Safety Executive said it was “aware of an incident that took place today at Swains Lane, Camden and is in communication with the emergency services”. A report had also “indicated ways to deal safely with the underground tanks” developers said.bHighgate councillor and Green London Assembly Member Sian Berry told the BBC that builders had been due to remove petrol tanks from the site this week. She said: “It’s absolutely shocking. I was there last Friday and saw a big tank that used to store petrol. The first stage of construction was taking these tanks away.