A renowned search-and-rescue dog whose career began at Ground Zeroafter the Sept. 11 attacks in New York City died Monday at the age of 16.

Bretagne, pronounced Brittany, was the last surviving search-and-rescue dog from the attacks. On Monday, because of declining health that included kidney failure, her handler, Denise Corliss, decided to have her euthanized.

Bretagne was 2 years old when she and Corliss, were part of the Texas Task Force 1 sent to the World Trade Center site in Lower Manhattan after the terrorist attack brought down the buildings on Sept. 11, 2001. They spent 10 days at the scene searching rubble for human remains.

About two dozen members of the Cy-Fair Volunteer Fire Department and members of Texas Task Force 1 formed a traditional wall of honor, saluting the golden retriever as she entered Fairfield Animal Hospital in Cypress. They were there to salute her again 30 minutes later as she was carried from the veterinary clinic draped in the Texas flag.

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"It's a hard day for the entire fire department,” said David Padovan with Cy-Fair Volunteer Fire Department. "She served her country. She served her community. And this is just a small way for us to honor her on her way out."

Bretagne also searched for survivors after Hurricanes Katrina and Rita.

Bretagne retired from active duty at age 9.

In retirement, she became a Cy-Fair celebrity. Bretagne was a mascot who served as an ambassador for Cy-Fair. She also became a therapy dog of sorts, a friend who first graders could read to at an elementary school in the Waller Independent School District.

"Just to see all the kids come alive when she walks in the door is absolutely wonderful,” Padovan said.

In 2014, Bretagne was nominated for a Hero Dog Award from the American Humane Association.

"She's part of Texas Task Force One. She's part of the Cy-Fair Fire Department. She's part of the Corliss family, to be honest. It's like they're losing a child,” said Chief Amy Ramon of Cy-Fair fire department. "It's very hard. Bretagne's part of our family. I've known her for her entire life and she's always been there. She's one of us. It's hard."

Even in death, Bretagne will be of service. She had been studied her entire life for the impact of 9/11 pollutants. She will undergo one last medical screening during an autopsy in College Station, Texas,

Contributing: The Associated Press. Follow Kevin Reece on Twitter: @KReeceKHOU