Police are appealing for witnesses following a serious road traffic collision on the M25 near Rickmansworth.
The incident occurred at around 2pm on Sunday (2 July), on the anti-clockwise carriageway between junction 16 and 17 heading towards Heathrow.
A white HGV lorry and a silver Volkswagen Passat Sport were in collision.
A man was arrested on suspicion of causing serious injury by dangerous driving and driving while unfit through drink or drugs.
The driver of the Volkswagen, a woman in her 60s, was airlifted to hospital with life-changing injuries.
Two of the four dogs in the Volkswagen also died in the collision. The remaining two dogs were taken to the vets for treatment.
Police are appealing for anyone who witnessed the collision or has dash cam footage to come forward.
Detective Sergeant Ben Heath, from the Serious Collision Investigation Unit, said: “Our enquiries are continuing as we look to establish the full circumstances of this collision, and we are appealing for anyone with information to please get in touch.
“Were you driving in the area at the time and saw what happened? Additionally, if you have a dash cam fitted, please check it as you may have recorded some crucial footage that may assist our investigation.”
If you have any information, please contact email@example.com. or on 101 quoting reference number 41/53214/23.
You can also contact the independent charity Crimestoppers anonymously on 0800 555 111.