An air ambulance landed on Sutton Green after police and paramedics were called to Jengar Close around 1.30am today (May 8).
An eyewitness saw doctors and officers “running” towards the street, with the first arriving in four minutes.
A child was treated at the scene before being taken by road to hospital “as a priotity”.
The severity or nature of their condition is not known at this stage.
A London Ambulance Service spokesperson said: “We were called at 1.38pm today (8 May) to reports of a medical incident on Jengar Close, Sutton.
“We sent resources to the scene, including an ambulance crew, a paramedic in a fast response car and an incident response officer. We also dispatched London’s Air Ambulance.
“Our first paramedics arrived in four minutes.
“We treated a child at the scene and took them to a major trauma centre by road as a priority.”
The Metropolitan Police has been contacted for details.
