A seven-year-old girl has died in hospital after suffering "critical injuries" in an incident on Friday morning (November 3).
The girl was treated by medical staff at the property in Blenheim Road, Wimbledon, after emergency services were called at around 8am.
A spokesman for the Metropolitan Police said: "A seven-year-old girl was found at the scene suffering critical injuries.
"The girl was taken to a south-west London hospital where her condition was life-threatening."
The Met later said the girl died on Saturday morning (November 4).
Her next of kin have been informed and a post-mortem examination will be held in due course.
One neighbour in Wimbledon, who asked not to be named, described arriving home as emergency crews dealt with the situation.
The man said: "I had been taking my kids to school, I turned into this road and thought it was strange because the cop cars were driving on the wrong side of the road.
"They were all double-parked, you couldn't get down further than my house really.
"There was a woman carrying all the medical gear into the house and you could tell by the look on her face.
"With coppers you can sometimes be all casual, go up and have a chat about what's going on. But you could see in their faces that something was very wrong. "
- Robert Peters, 55, appeared before Wimbledon magistrates on Saturday morning (November 4) charged with attempted murder.
He is due to appear at Kingston Crown Court on December 1.