The brother-in-law of Britain's Prince Charles died in New York on Wednesday after suffering a head injury in a fall, the prince's official residence announced.
Mark Shand, brother of Camilla, Duchess of Cornwall, "died in a hospital as a result a serious head injury which he sustained during a fall" on Tuesday night, Britain's Clarence House said in a prepared statement.
"The Duchess, The Prince of Wales and all her family members are utterly devastated by this sudden and tragic loss," the statement reads.
The Elephant Family, a conservation group based in England, mourned the loss of its chairman and the "head of our family."
"Mark Shand was a true force for conservation. He was both a legend and inspiration and above all our great friend," the organization said in a statement on its website.
CNN profiled the charity, which was working to improve conditions for Asian elephants, in 2007.
Shand said he was trying to show owners and riders more humane ways to treat the animals.
"You can't stop a tradition that's been going on for years, you can only help it," he said. His group also fought against poachers and the destruction of the elephants' habitats.
Shand also was the author of several books about elephants and his travels in Asia. One of those books, "Queen of Elephants," was the source for a BBC documentary.