Rifka bounded into the rubble of the Hanwang Town People's Hospital panting and barking. She had picked up the scent of death.
Rifka, a Belgian shepherd, was one of four dogs from Netherlands-based Signi Search Dogs hunting for the body of Qing Hong, an X-ray technician.
More than 23,000 people are still missing after the massive earthquake in southwestern China's Sihuan province two weeks ago.
After being guided by local residents in this devastated town, Saad Attia and his two colleagues from Signi believed Qing Hong was one of them.
There was nothing left of Hanwang's hospital except a dangerous mound of orange-brown bricks, twisted metal, broken wood and soggy medical texts. Some of the debris was more than three metres (10 feet) high.
With her bark, Rifka had signalled that a body might lie underneath but the searchers wanted confirmation.
"We're going to check it again with another dog," said Attia.
The job went to Finder, a three-year-old on her first overseas mission.
A nail punctured her lower left leg earlier in the quake zone but after several stitches and a dose of painkillers, Finder was still on the job, with a bandage above her paw.
The dog slid down what might have been a slab of wall, then climbed back over the debris.
She gave the tell-tale bark and got her reward, a green tennis ball.
"I think the person is there," said handler Esther van Neerbus, 37, moving closer to the ragged edge of what was a stairwell.
"Our job here is finished," Attia said.
But another awaited them in the drizzle at the foot of misty mountains.
"I think we have a lot of work to do today," said Attia, 44, a moustachioed man who fled Saddam Hussein's Iraq 27 years ago. "It will be only dead bodies, I think. There are no survivors."
In six days of searching, they had not found anyone alive.
Van Neerbus said the team may have identified about 50 corpses but did not know for certain since they were usually not present for the long process of digging.
The veterinarian said she founded Signi 17 years ago because she wanted to do something to help people using the animals she loves.
The dogs, trained to find both the living and the dead, have worked in disasters around the world.
The team explained that dogs' noses are far more sensitive than those of humans.
Attia took time off his job in a metal factory to travel to the quake zone in Sichuan province to work with Signi. "This is my holiday," he quipped.
But Attia's light touch accompanied a recognition that this is serious work, partly because it helps ease the families' uncertainty.
"Then you know for sure that he is gone," Attia said. "And second, I think most important is to prevent disease. It's already a disaster but if you leave it... you've got a serious problem for the public health."
Attia recalled the tears of a woman whose husband the dogs located a day earlier. Discoveries like that validate their mission, he said, but the job takes an emotional toll.
"I can cry just like a child. And I don't care," he said.
A backhoe slowly rattled past on its way to the spot where Qing, the hospital worker, was believed buried.
"They are going to dig," Attia said before the searchers walked to their next assignment, the dogs straining at their leashes.
They approached a six-storey apartment building that had collapsed, leaving a tangled landscape of mattresses, clothes, broken household appliances, bricks, scraps of door frames, and structural beams.
Liu Daibin, 43, told the searchers that seven or eight of his relatives could be somewhere in this mess.
The dogs took turns poking their heads into the rubble. Their frequent barking signalled several locations which the handlers marked using torn pieces of red cloth.
"It could be five bodies. It could be 10. It could be more," Attia said.