An inquiry has begun to find out why a car stopped in the outside lane of the M25 resulting in the death of three women two of whom were sisters.
The accident happened at about 1630 BST on Saturday on the clockwise carriageway of the motorway between junctions 8 and 9 at Surrey.
The sisters were in a Peugeot 206 with their two female cousins when it is believed they stopped in the outside lane of the motorway.
Three of the women got out of the vehicle and were standing in one of the lanes when they were hit by another car.
Carriageway closed
Police said all the women involved in the crash were in their 20s.
Two of the three who died were sisters aged 22 and 25.
The other woman who was killed was their cousin and was aged 22. Her sister, aged 25, survived the crash.
Police said all the women came from the Crawley area in West Sussex.
Two of the victims were pronounced dead at the scene and the third was taken to Epsom Hospital where she died from her injuries.
Treatment for shock
The fourth woman, who had remained in the car, was treated in hospital for minor injuries.
A spokeswoman for Surrey Police said: "The circumstances appear to be that a silver Peugeot 206 stopped in lane four of the carriageway.
"Three of the four occupants of the car got out.
"They were then struck by a white Mercedes panel van which was then in collision with an MG sports car which was on the hard shoulder."
The van driver was treated for shock and the MG driver was unhurt.
Police are appealing for any witnesses to the accident which resulted in the clockwise carriageway being closed for several hours.