A man was rushed to a trauma unit after "falling from a height".
The London Ambulance Service and London's Air Ambulance were called to Cathcart Hill, between Dartmouth Park and Tufnell Park, at 11.13am on April 15.
People on social media said a roofer working on a house had fallen - this paper is trying to confirm that.
The ambulance service said its first paramedic was on the scene in around a minute.
An ambulance service spokesperson said: “We were called at 11.13am on Monday, April 15, to reports of a fall from a height on Cathcart Hill.
“We sent resources to the scene including ambulance crews, paramedics in fast response cars, and an incident response officer.
"We also dispatched a trauma team from London’s Air Ambulance.
“Our first paramedic was on the scene in approximately one minute.
“We treated a patient at the scene and took them to a major trauma centre.”
The Metropolitan Police confirmed the person who fell was a man.
The Health and Safety Executive has been contacted to see if it is investigating.
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