Sophie, the Duchess of Edinburgh, has spoken out as an elderly woman fights for her life after being "thrown 40 feet across the road" by a police motorcycle escorting the royal.
The critically injured pedestrian, who is in her 80s, collided with the vehicle at around 3.20pm yesterday in Earl’s Court, West London.
An eyewitness told the Mirror how she had stepped out to peer around a junction before being thrown across the road.
Paramedics from the London Ambulance Service and London's Air Ambulance attended the scene, and the woman was taken to hospital.
She remains in a critical condition and her family have been informed.
It is not immediately clear where the Duchess was travelling to, but it came a day after she hosted the Buckingham Palace garden party with the Prince and Princess of Wales.
In a short statement, Buckingham Palace said: "The Duchess’s heartfelt thoughts and prayers are with the injured lady and her family.
"She is grateful for the swift response by the emergency services and will keep abreast of developments.
"Further comment at this time would not be appropriate while the incident is being investigated."
Retired antiques dealer Martin Hennessy, 62, lives yards from the site and saw police cars swarming the scene.
He claimed the woman had stepped out in the road to peer around black curtains shielding a junction box when she was hit by the bike.
Mr Hennessy, who has lived there for 40 years, said: “She’s lucky to be alive at all. The road is a nightmare. We’ve warned the council about it. There have been three people killed here.
“When you get to the junction you have to step out to see if anything is coming, that’s when she was hit.
“I came out to walk the dogs and that when I saw this thoroughfare. She’d been thrown across the road and the ambulance were treating her."
Another person who lives nearby described the road as "dangerous", and wrote on Facebook: "This road is awful - it scares me."
No other injuries were reported, said the Metropolitan Police, and enquiries into the crash are ongoing.
In an updated statement this morning, the force confirmed that an investigation has been launched by the Independent Office for Police Conduct (IOPC).
A police spokesperson said: “A woman has been injured after being involved in a collision with a police motorcycle in west London.
"At approximately 15:21hrs on Wednesday, 10 May a police motorcycle on escort duties was involved in a collision with a member of the public on West Cromwell Road, Earls Court, SW5.
"Paramedics from the London Ambulance Service and London's Air Ambulance attended and a woman, aged in her 80s, was taken to hospital. She remains there in a critical condition. Her family have been informed.
"There are no reports of any other injuries.
"An independent investigation has been launched by the IOPC."
The Met Police’s Special Escort Group provide armed escorts for Royal Family members, VIPs, protected members of the Government, visiting royals, heads of state and other visiting dignitaries.
The IOPC confirmed that an investigation was launched into the collision last night, and said it is "at a very early stage".
A spokesperson told the Mirror: "Last night (10 May) we began an independent investigation after we were informed by the Metropolitan Police Service (MPS) of an incident where a police motorcycle on escort duties collided with a woman on West Cromwell Road, Earls Court (SW5) around 3.21pm yesterday afternoon.
"The woman, who is in her 80s, sustained serious injuries and was taken to hospital, where she remains in a critical condition.
"Last night we sent investigators to the scene and to the post incident procedures to begin gathering evidence.
"In due course we will be in touch with the woman’s family to express our sympathies and explain our role.
"Our investigation is at a very early stage.”
