King Charles III was on Saturday said to be "deeply saddened" after police said a British relative of his sons' former nanny was among the victims of the deadly truck-ramming attack in New Orleans.
Edward Pettifer, 31, who died in the atrocity, was the stepson of Prince William and Prince Harry's former nanny Tiggy Pettifer.
It was "understood the King was... deeply saddened, and had been in touch with the family to share personal condolences", the UK's Press Association news agency said in a report.
Heir to the throne Prince William said he and his wife Catherine had also been "shocked and saddened by the tragic death of Ed Pettifer".
"Our thoughts and prayers remain with the Pettifer family and all those innocent people who have been tragically impacted by this horrific attack," he wrote on the couple's Kensington Palace social media account.
Pettifer's half-brother Tom is one of William's godsons and was a page boy at his wedding to Catherine, the Princess of Wales, in 2011.
In 1993, Charles employed Tiggy Legge-Bourke, now Pettifer, whose family had longstanding links to the royals, as a nanny for William and his younger brother Harry after his separation from their mother, Princess Diana.
"The entire family are devastated at the tragic news of Ed's death in New Orleans. He was a wonderful son, brother, grandson, nephew, and a friend to so many. We will all miss him terribly," the Pettifer family said in a statement.
On New Year's Day a US army veteran, who the FBI says pledged loyalty to the Islamic State jihadist group, used a pickup truck to kill and wound revellers in New Orleans's crowded French Quarter, before being killed by police.
Foreign Secretary David Lammy said he was "extremely saddened" to learn a British man had been among those killed in the attack.
"We are supporting his family and stand united with the US against terror threats," he wrote on X.
- AFP