Four people were killed - an unarmed police officer, a mother of two, an American tourist and a south London pensioner - and 50 others were injured after a terrorist brought terror to the heart of Westminster.
Khalid Masood drove at pedestrians on Westminster Bridge before crashing his hire car and stabbing to death Pc Keith Palmer, a 48-year-old husband and father, at the gates to the Houses of Parliament.
Masood's three victims on Westminster Bridge were Aysha Frade, a 43-year-old British mother; Kurt Cochran, a US tourist from Utah; and 75-year-old Leslie Rhodes, from south London.
Pc Keith Palmer
Pc Palmer had worked for the Metropolitan Police for 15 years, having previously served in the armed forces.
"He was someone who left for work today expecting to return home at the end of his shift - and he had every right to expect that would happen," Mr Rowley said.
Online donations have poured in for Pc Palmer on JustGiving, with thousands of pounds already raised to help support his family.
Statement from his family: 'We love him so much'
"Keith will be remembered as a wonderful dad and husband. A loving son, brother and uncle. A long-time supporter of Charlton FC.
"Dedicated to his job and proud to be a police officer, brave and courageous. A friend to everyone who knew him.
"He will be deeply missed. We love him so much.
"His friends and family are shocked and devastated by his loss and ask that they are left to grieve alone in peace."
'A lovely man, a friend': Ex-colleague, James Cleverly MP
"I've known Keith for 25 years. We served together in the Royal Artillery before he became a copper. A lovely man, a friend. I'm heartbroken," James Cleverly MP said.
"My thoughts are with the family, friends and colleagues of PC Keith Palmer. A brave man."
Mr Cleverly choked back tears as he remembered his friendship with the police officer on Thursday.
His voice breaking, Conservative legislator James Cleverly called for Constable Keith Palmer to receive posthumous recognition for his "gallantry and sacrifice."
He said he first met Palmer 25 years ago as "Gunner Keith Palmer" when both men served in the Royal Artillery.
Cleverly said the 48-year-old police officer was "a strong, professional public servant and it was a delight to meet him again only a few months after being elected."
Prime Minister Theresa May said Palmer had "paid the ultimate sacrifice here at the heart of our democracy" and that the suggestion of posthumous recognition would be considered.
Paying tribute to the officer, the Mayor of London Sadiq Khan said: "Keith Palmer was killed while bravely doing his duty - protecting our city and the heart of our democracy from those who want to destroy our way of life.
"My heart goes out to his family, friends and colleagues.
"He personifies the brave men and women of our police and emergency services who work around the clock to keep us safe - tonight all Londoners are grateful to them."
We all mourn for PC Keith Palmer and send the deepest condolences to his family. He died protecting all of us at Westminster.
— Ed Miliband (@Ed_Miliband) 22 March 2017
Tributes were paid to him by MPs, including former Labour leader Ed Miliband who said: "We all mourn for PC Keith Palmer and send the deepest condolences to his family. He died protecting all of us at Westminster."
Labour MP Keir Starmer said: "Thank you PC Keith Palmer. No need for words about us or Parliament. Just all thoughts to your family."
Chairman of the Metropolitan Police Federation Ken Marsh expressed "deepest sympathy" to the officer's family.
I've known Keith for 25 years. We served together in the Royal Artillery before he became a copper. A lovely man, a friend. I'm heartbroken. https://t.co/LgF4rQ7Vmg
— James Cleverly MP (@JamesCleverly) 22 March 2017
He added: "This incident sadly shows the dangers our colleagues face on a daily basis. They show incredible bravery protecting the public."
Chairman of the Police Federation of England and Wales Steve White said "no words can capture how members of the policing family will feel".
The husband of murdered MP Jo Cox has said the "name I will remember" from the Westminster atrocity is Pc Keith Palmer - not his killer.
I don't care about the name of the attacker. This is the name I will remember. https://t.co/2azZHWkJAk
— Brendan Cox (@MrBrendanCox) 22 March 2017
Brendan Cox, whose wife was stabbed and shot by a right-wing extremist outside her constituency office last June, said the identity of the suspected terrorist was irrelevant.
Sharing a picture of Mr Palmer on his Twitter feed, he wrote: "I don't care about the name of the attacker.
"This is the name I will remember."
Explaining why Pc Palmer was unarmed, Mr Rowley said: "Our parliamentary protection team are a combination of armed and unarmed officers doing different roles, and sadly the officer who lost his life today was unarmed.
PC Keith Palmer was killed doing his duty - protecting our city and our democracy from those who want to destroy our way of life. pic.twitter.com/hTI1Qqw6M3
— Mayor of London (@MayorofLondon) 22 March 2017
"He was supported by armed colleagues who shot and killed the attacker.
"He (the attacker) tried to enter Parliament and was stopped at the gate."
Greater Manchester Police chief constable Ian Hopkins added: "#RIP PC Keith Palmer, brutally murdered today carrying out his duty helping to protect Parliament and the freedom of our Country."
The Metropolitan Police Federation, which represents officers from the force, said: "PC Keith Palmer. Our brave Met Police colleague who today made the ultimate sacrifice #LestWeForget"
A chorus of thanks also came from politicians on all sides of the House.
Thank you PC Keith Palmer - to your bravery many others owe their lives and safety https://t.co/gTMLdsqN34
— Yvette Cooper (@YvetteCooperMP) 22 March 2017
Home Affairs Select Committee chairwoman Yvette Cooper, who was in the Palace of Westminster when the terrorist burst through the gates, said: "Thank you Pc Keith Palmer - to your bravery many others owe their lives and safety"
Labour MP Barry Gardiner was also caught up in the lockdown and posted a picture of armed police moving through Parliament.
He tweeted: "Going to bed alive, safe and well thanks to Pc Keith Palmer. God bless him, his family and all those killed or injured. Terror will not win."
Geoffrey Cox, Conservative MP, wrote: "Deeply sad that a brave Pc, Keith Palmer, died in the service of his country, doing his duty today. We should be proud to know such men."
MP Chi Onwurah tweeted: "As I left Parliament a police officer apologised for keeping us waiting. Cannot overstate courage & grace of those who protect us Thank you."
The last death of a Met Police officer on duty was in September 2013 when 47-year-old Pc Andrew Duncan was killed as he attempted to stop a speeding vehicle in Sutton, south London.
Aysha Frade was strolling across Westminster Bridge on the way to collect her children from school when Khalid Massood charged down the pavement in a 4x4 and snatched her life away, Henry Bodkin and Eleanor Steafel report.
She had just come from work, a school itself, where she dedicated herself to helping youngsters learn the language and culture of her family’s beloved native Spain.
On Thursday, in the quiet Galician town of Betanzos, more than 100 locals, burdened by “tragedy and enormous pain”, gathered in silence to remember the 43-year-old, who died amid sirens and screams at the heart of a global city.
Back in London, her Portuguese-born husband John Frade’s life had “completely fallen apart”, according to a cousin.
He now must face the reality of bringing up two children, aged eight and 11, without a mother, described by those who knew her as “kind” and the “most upstanding member of society”.
A shell-shocked neighbour, Patricia Scotland, who first met Mrs Frade when she began dating the her future husband, said the couple had been a “lovely family”.
"I just can't believe what I'm hearing this morning,” she said.
"She was such a kind lovely woman."
The first of the two civilian victims to be named, Mrs Frade died within view of the DLD sixth form College just off the south bank of Westminster Bridge, where she served as a department head.
On Thursday, the principal, Rachel Borland, said the death of her colleague was a “devastating loss”.
“She was highly regarded and loved by our students and by her colleagues - she will be deeply missed by all of us,” she said.
Born in London to a Galician mother and Cypriot father, Mrs Fade’s gift for teaching languages runs in the family.
In Betanzos, where she often spent her summers, the language centre run by her two older sisters, Silvia and Michelle, was closed yesterday as they reeled from the devastating news.
A cousin told Spanish radio: “I am crushed. We never expected anything like this.”
“Yesterday I got a call from Silvia. She said “something terrible has happened. Aysha has been killed”.”
Andreas Hermida, a local politician who knows the family, said Mrs Frade had many friends in the town, where two days of mourning was declared.
"It's an immense tragedy and an enormous pain - there is a big sadness in Betanzos,” he said.
Kurt Cochran was the hard-working family man who nevertheless lived his dream, Henry Bodkin and Ruth Sherlock report.
The rock-obsessed American, who ran his own music studio, was enjoying the final day of a trip of a lifetime with his wife to celebrate the couple’s 25th anniversary.
But as dusk fell on Wednesday, Kurt, 54, lay dead at the mouth of a concrete underpass beneath Westminster Bridge, while a shattered Melissa, 46, was being treated in hospital for a broken leg, ribs and cuts to the head.
A great American, Kurt Cochran, was killed in the London terror attack. My prayers and condolences are with his family and friends.
— Donald J. Trump (@realDonaldTrump) March 23, 2017
Mr Cochran was thought to have jumped from the bridge to avoid Kahlid Masood’s rampaging 4x4.
The couple, who live near Salt Lake City, had already visited Germany and had been excitedly sharing photographs of their trip with friends on social media.
On Thursday, however, a distraught relative, Shantell Payne, used the same platform to break the news of Mr Cochran’s death.
“With a heavy heart I must pass the sad news of our beautiful brother, father, husband, son and friend Kurt Cochran, he could not overcome the injuries he received in the London terror attacks,” she wrote.
"This pain is so heart wrenching and raw it has rocked our family and all that knew him to its core. We will miss Kurt beyond words."
A friend told the Telegraph Mr Cochran was extremely generous with his recording studio and would let it out for free to help musicians build their careers.
“It can be hard when you’ve got responsibilities in daily life to dive into your dream, but he did just that” said Nate Kizerian.
“He gave it all to make it happen and he succeeded.”
Mr Cochran grew up in Maryland and lived in Texas for a time before settling in Utah in 1983.
President Donald Trump tweeted: “A great American, Kurt Cochran, was killed in the London terror attack. My prayers and condolences are with his family and friends.”
The fourth member of the public injured in the attack, who died in hospital on Thursday night, was 75-year-old Leslie Rhodes from Streatham, south London.
His MP, Chuka Umunna, spoke of his sadness on Twitter:
1/2 Deeply saddened to hear that my constituent Leslie Rhodes has died from the injuries he sustained in Wednesday's shocking & awful attack
— Chuka Umunna (@ChukaUmunna) March 24, 2017
2/2 The thoughts and prayers of all our community are with Mr Rhodes' family and friends - we can only imagine what they are going through
— Chuka Umunna (@ChukaUmunna) March 24, 2017
Mr Rhodes is thought to have been visiting a nearby hospital when he was mown down by the car, reports Henry Bodkin.
Neighbours paid tributes to the retired window cleaner, 75, as "a lovely man" and said he had been "as fit as a fiddle" despite his age.
Philip Williams, 61, said: "We'd known him for 24 years. He was a lovely man. He would do anything for anybody. And it's such a shock."
Mr Rhodes - a retired self-employed window cleaner - was not married and had no children, Mr Williams said.
He added: "You know, it's a crime that he's been taken."
Mr Williams said he had been told by neighbours who went to see him before he died that Mr Rhodes was attending the hospital and may have been coming from or going to a bus stop nearby when he was hit.
He said: "I've been told he was at the hospital, St Thomas', and he went by public transport and he was apparently crossing the bridge when this car hit him.
"As I say, I've been told he was hit in the midriff. He had many broken bones. Apparently he went into a coma straight away."
Mr Williams added: "I came to take the dog out this morning and the first thing I saw was his car and I burst into tears.
"He would do anything for you. He would help clean your windows or take your rubbish out.
"The thing I always remember was how kind he was. He was a very, very kind man. To lose a man like that is devastating.
'He was incredibly fit and used to cycle a lot. We'd pass the time of day and chat about cricket, which he loved."
Mr Williams said Mr Rhodes had grown up in the block of flats he was living in when he was killed.
Those injured included 12 Britons, three French children, two Romanians, four South Koreans, two Greeks, and one each from Germany, Poland, Ireland, China, Italy and the United States.
Three police officers were also hurt, two of them seriously.
Colleen Anderson, a doctor at St Thomas' Hospital, said on Wednesday that some people who were on the bridge suffered "catastrophic injuries".
A woman who fell into the Thames was rescued and given urgent medical treatment on a nearby pier.
The Romanian Embassy in London confirmed the woman's name as Andreea Cristea. They embassy also said the other Romanian person injured in the attack is Andrei Burnaz, understood to be the woman's partner. He reportedly suffered a foot fracture.
A Romanian diplomat said the woman has successfully undergone surgery and she remains in a critical state.
Romania's Ambassador to Britain, Dan Mihalache, told national news agency Agerpres on Thursday that she had major problems with her lungs.
A party of French schoolchildren were among those targeted on the bridge, while four students from Edge Hill University in Ormskirk were also hurt - two described as "walking wounded", and another couple said to have minor injuries.
Three school children on a trip from France are among the injured in the London terror attack, their teacher has told The Telegraph. Two of them are believed to be in a critical condition.
A spokesman for the French foreign ministry confirmed that three pupils from the Saint-Joseph high school in Concarneau, Brittany, were among the injured. Bernard Cazeneuve, the French prime minister, later tweeted: "Solidarity with our British friends struck terribly, full support to the injured French pupils, their families and their classmates."
Two of the three pupils are in a "critical condition" and the third is in the operating theatre, according to parents who spoke to local media in Brittany.
South Korea's foreign ministry said that five South Koreans in their fifties and sixties were among the injured.
The ministry said they were hurt when they were caught up in a stampede of people trying to escape the attack.
It says four of the South Koreans suffered broken bones and other injuries and a woman in her late sixties needed an operation to treat a head injury.
Romania's foreign ministry said that two Romanians were wounded in the attack and had been taken to a hospital for treatment. There were no further details on the identity of the two or how seriously they were injured. The ministry said it had been informed by authorities in London.