Prince William, Kate Middleton and Prince Harry Attend Service of Hope for London Terror Attack Victims

Four people were killed in Westminster on March 22

It was a somber afternoon in London Wednesday.

Prince William, Kate Middleton and Prince Harry arrived at Westminster Abbey for a multi-faith Service of Hope, which was held for the four people killed during the London terror attack on March 22. After laying a wreath, they spoke to a clergy member before saying hello to London Mayor Sadiq Khan and Metropolitan Police acting commissioner Craig Mackey

The royal family's wreath included handwritten message that read: "For PC Keith Palmer, and all those who have served our community so valiantly. Your legacy is our way of life. William."

Each member of the congregation was given a candle upon their arrival at Westminster Abbey. More than 400 faith leaders, firefighters, medics and police officers attended the service; two hundred diplomatic representatives from across the world also came out to show their support.

The service took place exactly two weeks after Khalid Masood mowed down dozens of people along Westminster Bridge and fatally stabbed a police officer near the Houses of Parliament. From start to finish, the incident lasted 82 seconds—and Masood was shot dead on the scene.

Several victims—including Melissa Cochran, Travis Frain and Trish Neis-Beer—attended Wednesday's service, as did relatives of college worker Aysha Frade, who died on the bridge. Kurt Cochran, Leslie Rhodes and police officer Keith Palmer were also killed during the attack.

The invite-only service began at noon and was broadcast across the U.K. The Very Reverend Dr. John Hall, Dean of Westminster, presided over the ceremony. Home Secretary Amber Rudd did the first reading, followed by the Duke of Cambridge, who read a bible passage from the Gospel of Luke. Before the service began, Rudd said, "Today's Service of Hope marks two weeks since a cowardly attacker tried—and failed—to divide the people and the communities of London and cause us to live in fear and suspicion. But we were not cowed, and we did not give in to terror."

The service ended with the Our Father prayer, a hymn and the national anthem.

The Duke of Cambridge previously visited St. Thomas to meet staff and also met with London Ambulance Service paramedics who took patients to the hospital. His father, Prince Charles, also visited injured victims in King's College Hospital in Southwark two days after the incident.

One day after the attack, at a mental health charity event, Middleton shared her sympathies. "I know you would all want to join me in sending our thoughts and prayers to all those sadly affected by yesterday's terrible attack in Westminster," she said in her opening remarks. "We will be thinking of all the families as we discuss the important issues we're here to talk about."

Palmer's funeral, meanwhile, will take place at Southwark Cathedral on Apr. 10.