While speaking with first responders who rushed to help survivors of a deadly knife attack in Southport earlier this year, the Princess of Wales, 42, shared how much of an impact they had on grieving parents.

According to HELLO!, she told firefighters, officers and other heroes "how grateful they all are for the support you provided on the day. ... For you to witness that, you need support yourselves."

Prince William, 42, added, "You're all heroes. Please make sure you look after yourselves; take your time, don't rush back to work."

According to Sky News royal correspondent Rhiannon Mills, who was covering the couple during their surprise joint appearance, the moment was singular.

"It was one of the most emotional and candid conversations I've ever listened to on a royal visit," she told HELLO! on Monday, October 14. "[Kate] was engaged and visibly moved by what she was hearing from the first responders as they bravely shared their experiences. With William alongside her, you could see that they had both wanted to travel to Southport to show the community that they hadn't been forgotten."

On Thursday, October 10, Kate surprised royal watchers when she stepped out with her husband for a trip to the Southport Community Centre.

The event would mark her first public event since completing chemotherapy last month. Kate previously underwent abdominal surgery in January and confirmed nearly two months later that she had been diagnosed with an undisclosed form of cancer.

"This was a big moment for Kate in her recovery journey, but a visit she wouldn't have missed," Rhiannon told HELLO! "There was no sign of the personal challenges she has faced this year."

Instead, Kate appeared to focus on the first responders who experienced so much when three young girls -- Alice Dasilva Aguiar, 9, Elsie Dot Stancombe, 7, and Bebe King, 6 -- died during a stabbing that took place at a Taylor Swift-themed dance class in July.

Two adults and nine children were also injured during the incident. A 17-year-old boy was later arrested and charged with the murders.

"The Princess of Wales broke off and came back into the building to give a hug to the people who responded, because she could see the emotion in them and could see it was different for them to relay their feelings," Chief Fire Officer for Merseyside Fire & Rescue Service Phil Garrigan told HELLO! "I think that shows a really caring side and is very, very touching for them."