SURFSIDE, Fla. (NewsNation Now) — As rescue teams comb through the remains of a partially-collapsed condo building in Florida, man’s best friend is there to hopefully point them in the right direction.

Specially trained dogs are sniffing for clues about the 99 missing residents.

Sinead Imbaro trains police and military dogs. She says the dogs are looking for one of two things: human breath or human odor.

“It’s really that live breath that they’re looking for,” Imbaro said on NewsNation Prime. “For confirmation that there’s somebody hidden in that pile, once they get, or once they locate that breath, or human odor, they will begin to bark for the alert.”

If someone can scream for help, the dog’s impact is minimalized. But they could be invaluable in finding people who might be incapacitated.

She says it can take up to 2 1/2 years to properly train a dog for this type of work. “[There] has to be a good relationship with the handler and dog in order to go in and seek out the victims,” she said.

The dogs are not canaries in the coal mine, however. Engineers confirm an area is safe enough for dogs (or people) before they go in, but first aid is always on stand-by.

“We try our best to keep them safe as we try to keep ourselves safe,” Imbaro said.