An officer on duty, a teacher, a pensioner and a tourist celebrating his wedding anniversary with his wife – the world is learning more about the four people killed in Wednesday’s attack in Westminster.

The third victim of the terror attack in Westminster has been named as American Kurt Cochran.

Mr Cochran was visiting London with his wife Melissa to celebrate their 25th wedding anniversary.

His wife was injured in the attack and she is in hospital with a broken leg, rib and a cut to the head.

On Thursday evening police confirmed that a 75-year-old man, the fourth victim, had died in hospital as a result of the attack. His life support was withdrawn, detectives said.

A Facebook post by the Cochrans' family described the loss of the 54-year-old as "heart wrenching".

It said: “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. 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. We love you Kurt. RIP. Melissa Payne Cochran is in the hospital with a broken leg, rib and a cut on her head but will recover from her injuries. Sending all the love to her for a quick recovery.”

Kurt Cochran was visiting London with his wife Melissa (Facebook/Shantell Payne)

A statement from Ms Cochran's side of the family said: “Our family is heartbroken to learn of the death of our brother and son-in-law, Kurt W. Cochran, who was a victim of Wednesday’s terrorist attack in London.

“Kurt was a good man and a loving husband to our sister and daughter, Melissa.

“They were in Europe to celebrate their 25th wedding anniversary, and were scheduled to return to the United States on Thursday.

“Melissa also received serious injuries in the attack and is being cared for in the hospital.”

US President Donald Trump tweeted condolences to Mr Cochran.

He said: “A great American, Kurt Cochran, was killed in the London terror attack. My prayers and condolences are with his family and friends.”

Mr Cochran was the third person who died in the attack to be named.

Aysha Frade

Aysha Frade was walking to pick up her daughters from school when she was killed (Facebook)

Aysha Frade, who worked as a sixth form Spanish teacher at the nearby DLD College London, also died in the attack.

A British national, whose mother was Spanish and father was Cypriot, she lived in London with her two young daughters and her husband.

She was walking to meet her daughters from school when the attack happened.

The school’s head teacher Rachel Borland said Ms Frade was “a highly regarded and loved” teacher at the college. “She will be missed by us all.”

A former neighbour of Ms Frade, Patricia Scotland, who lives in the Ladbroke Grove area of London told the BBC Ms Frade had been a “lovely mother, a lovely wife”.

"She was just a lovely person, with two lovely, lovely girls," she said. "You couldn't ask for better neighbours".

PC Keith Palmer

PC Keith Palmer was on duty and unarmed when he was stabbed by the attacker (Metropolitan Police)

PC Keith Palmer, 48, was stabbed by the attacker who was attempting to gain entry to the Palace of Westminster.

PC Palmer was on duty as an unarmed member of the Parliamentary and Diplomatic Protection Squad at the Houses of Parliament.

He had been in the Metropolitan Police since 2001 and has a five-year-old daughter.

A statement from PC Palmer’s family said: “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.”

Conservative MP and former colleague James Cleverly described the police officer as “a lovely man, a friend.”

“I’m heartbroken,” he said.

In a moving tribute to PC Palmer in the House of Commons, Mr Cleverly later described him as a “strong, professional public servant”, while Prime Minister Theresa May said he was “every inch a hero and his actions will never be forgotten.”

Charlton Athletic Football Club, paid tribute to PC Palmer by placing a scarf on the seat he occupied in the stands as a long-time season-ticket holder.

Over £225,000 has been donated after the Metropolitan Police Federation launched a memorial fund to pay tribute to their “fallen colleague”, who they say was “simply doing his job” when he was senselessly targeted while guarding the Palace of Westminster.

A JustGiving page launched just after 9am on Thursday reached its target of £10,000 in less than two hours.

Injured

At least 40 people were injured in the attack, including a Romanian woman who has undergone major surgery, including the removal of a blood clot on her brain. Her fiancé also sustained a broken foot.

Three French school children were also struck by the car as it drove along the pavement on Westminster bridge. One boy is in intensive care with broken legs, a head injury and a localised haematoma behind one of his lungs.

Two police officers are also believed to be in a serious condition in hospital, while another is reportedly stable. The group were returning from an event that recognised their bravery in service, according to the Metropolitan Police.

Two British students were also injured, with one requiring stitches for a head wound, while the other sustained a wrist injury.

In total five people remain in a critical condition and two have life threatening injuries.

Attacker