When asked about their preference of furry companion, 70% of Americans describe themselves as “dog persons,” rather than the 20% who say they are “cat persons.” People love dogs due to their friendly nature and fierce loyalty.

But how loyal can a dog really be? Well, if they’re anything like Tillie, it could be enough to save a life.

According to Amy Carey of Vashon Island Pet Protectors, a Washington state animal shelter, setter mix Tillie stood guard for nearly a week to protect her basset hound companion Phoebe, who had fallen into a cistern.

The two were found on September 15th by Vashon Island Pet Protectors after their owners had reported them missing.

B.J. Duft, Tillie and Phoebe’s owner, said the dogs disappeared while he was hosting a company party at his home on September 7. He believes that the door was left open, which allowed the dogs to slip out.

”Tillie would never leave even if the gate was left open, but she’s best friends with Phoebe,” Duft said to ABC News. He says that wherever Pheobe’s nose takes her, Tillie goes along to make sure she’s okay. “They’re best pals – inseparable.”

Duft says he’s had 11-year-old Tillie since she was a puppy, but only adopted 4-year-old Phoebe two years ago after the dogs met at a doggie daycare.

After about a week of fruitless searching, Vashon Island Pet Protectors got a tip from a community member who said he saw a dog in his yard.

“A community member said he saw a dog for the past few days coming up to his property, come up near him but not all the way, and then go back down a trail to a ravine behind the house,” said Carey, who works for the organization. “It turned out the dog was Tillie trying to get help for Phoebe, who had gotten stuck.”

Immediate investigation revealed Phoebe stuck in the ravine, and Tillie standing over it watching guard.

“It was very clear what Tillie had done,” said Carey. “She had not left her friend’s side except for going up to the man’s house when he was there to try and get help for Phoebe.”

The dogs have been rescued and were reunited with Duft, who said the pups were exhausted but were otherwise in good health. He said he has also purchased a GPS dog collar so he will never lose his companions again.