This video shows the dramatic moment a woman was rescued from the Thames following the Westminster Bridge terrorist attack.
Romanian tourist Andreea Cristea, 29, was visiting London with her fiance for his birthday when she was ploughed into by a jihadist driving an SUV on the bridge.
It is not known whether she fell or jumped but initial reports suggested she leapt into the water to escape, the Daily Mail reports.
Miraculously, the Romanian architect was plucked to safety by a passing cruise ship.
The staff, on a City Cruises pleasure boat, could not get her out of the water but a nearby fire service boat came to her rescue.
A witness told the Sun: "They tried to fish her out with a pole but she was not responding. Then a rescue boat came and took her out."
The captain stopped the boat and held her out of the water to stop her being carried away by the current before emergency services took over, the spokesman said.
She was taken to hospital and underwent surgery last night to remove a clot. Although she showed signs of slight improvement, she remains in a critical condition under observation owing to problems with her lungs.
British man Khalid Masood, 52, killed three and injured at least 29 after mowing down pedestrians on the bridge before stabbing Metropolitan Police officer PC Keith Palmer outside the Palaces of Westminster on Thursday.
Cristea and her fiance had reportedly just visited Westminster Abbey and the London Eye before they were injured in the attack.
Footage of the incident captured her falling into the river.
Paramedics treated Cristea at a pier and she was taken to hospital. She had surgery overnight which was described as "successful" but remains in a critical condition.
Her fiancé, engineer Andrei Burnaz, who celebrates his birthday tomorrow, suffered a knee injury but has been discharged from hospital.
She had been due to marry Burnaz this spring and they had come for a holiday from their home in the Romanian city of Constanta.
City Cruises has confirmed a crew assisted fire services in the rescue operation yesterday.
Kyle Haughton, managing director at the firm, said: "City Cruises Millennium Diamond was in the area of the incident at the time and worked alongside London's emergency services to support in the rescue efforts of a woman in the water.
"Once alerted by people on the bridge, the ship's captain reacted fast on spotting her, he halted the boat in order to hold her out of the water and stop her from being carried any further by the current.
"The emergency services were called immediately and arrived within minutes to take over the rescue operation.
"On behalf of City Cruises, our thoughts are with the families of the victims of this incident."
One witness, bus driver Michael Adamou, 25, said he believed at least one woman had jumped into the Thames to escape.
"The first thing I saw was the two people laying lifeless on the floor," he said.
"I heard one guy come running behind me shouting his wife had jumped into the river to avoid getting knocked down."
The couple were due to meet a friend, retired surveyor Patrick Tracey, 64, from Derby, at the London Eye.
Tracey said: "I realised that my friends were over at Westminster Abbey coming to meet me and I got a telephone call from him.
"But I couldn't hear anything because of the din ... That was when he said he had lost Andreea. I don't know how seriously hurt she is. He was injured on his leg. I imagine it's the vehicle."
Paul Ciocoiu, a spokesman for the Ministry of Foreign Affairs in Romania, told Digi 24 TV: "According to information we have, she would be the pedestrian hit by a car and thrown into the Thames and then recovered. Ministry contacted the family.
"We do not know when the family arrived in Britain. If the family require consular assistance, of course, the ministry provides help punctually."
Dan Mihalache, the Romanian ambassador, said: "Right now, the state of the two Romanians injured is as follows: the woman is in a critical state because she has multiple injuries and a problem with the functioning of the lungs.
"She underwent a pretty complex surgery. Fortunately, she survived well this procedure and was moved to another hospital. Her state is still critical, but we hope she will overcome it."
He said Burnaz "has a foot fracture, but he is in a state of psychological shock."
Scotland Yard said eight people have now been arrested as part of the investigation into the Westminster terror attack, which left at least five people dead.