During the chaos of the 9/11 attacks, where almost 3,000 people died, nearly 100 loyal search and rescue dogs and their brave owners scoured Ground Zero for survivors.
A statement from the Texas A&M Engineering Extension Service says Golden Retriever Bretagne was put to sleep in June this year at a veterinary clinic in the Houston suburb of Cypress.
Bretagne (Pronounced: Britney) was two years old when she and her handler, Denise Corliss, took part in the 9/11 search operation in New York.
They spent 10 days at the scene searching rubble for human remains.
Nearly 100 other search and rescue dogs were used after 9/11 to try to find and save people trapped in the rubble of the World Trade Centre.
Bretagne retired from active duty aged nine.
After retiring, Bretagne helped other search dogs and volunteered at a reading programme at a primary school in Texas.
She was also a 2014 finalist for the American Humane Association’s annual Hero Dog Awards.