'Miracle' if searchers find woman who fell in sinkhole alive, police say.

The search for a woman who is believed to have fallen into a sinkhole in western Pennsylvania has become a recovery effort after two treacherous days of digging through mud and rock produced no signs of life, authorities said on Wednesday.

Pennsylvania State Police spokesperson Trooper Steve Limani said during a news conference that authorities no longer believe they will find 64-year-old Elizabeth Pollard alive, but that work to find her remains continues.

“We’ve had no signs of any form of life or anything” to make rescuers think they should “continue to try and push and rush and push the envelope, to be aggressive with the potential of risking harm to other people,” Limani said.

He noted that oxygen levels below ground were insufficient.

Emergency crews and others have been trying to locate Pollard for two days.

Her relatives reported her missing early Tuesday and her vehicle with her unharmed 5-year-old granddaughter inside was found about two hours later, near what is thought to be a freshly opened sinkhole above a long closed, crumbling mine.

“We feel like we failed,” Limani said of the decision to change the status of the effort from a rescue to a recovery. “It’s tough.”

Limani praised the crews who went into the abandoned mine to help remove material in the search for Pollard in the village of Marguerite, about 65 kilometres east of Pittsburgh.

“They would come out of there head to toe covered in mud, exhausted. And while they were getting pulled up, the next group’s getting dropped in. And there was one after the next after the next,” Limani said.

Authorities had said earlier that the roof of the mine had collapsed in several places and was not stable.

“We did get, you know, where we wanted, where we thought that she was at. We’ve been to that spot,” Pleasant Unity Fire Chief John Bacha, the incident’s operations officer, said earlier Wednesday.

“What happened at that point, I don’t know, maybe the slurry of mud pushed her one direction. There were several different seams of that mine, shafts that all came together where this happened at.”

Searchers were using electronic devices and cameras as surface digging continued with the use of heavy equipment, Bacha said.

In the coming days, they plan to greatly widen the surface hole, with winter weather forecast in the region.

Sinkholes occur in the area because of subsidence from coal mining activity.

Rescuers had been using water to break down and remove clay and dirt from the mine, which has been closed since the 1950s.

Crews had lowered a pole camera with a sensitive listening device into the hole, but it detected nothing. Another camera lowered into the hole showed what could be a shoe about 9 metres below the surface, Limani said Tuesday.

Searchers also deployed drones and thermal imaging equipment to no avail.

Pollard’s family called police at about 1 am on Tuesday to say she had not been seen since going out at about 5 pm Monday to search for Pepper, her cat.

The temperature dropped well below freezing that night.

Limani said the searchers met with her family before announcing the shift from rescue to recovery.

“I think they get it,” Limani said.

Pollard’s son, Axel Hayes, described her as a happy woman who liked going out to have fun.

She and her husband adopted Hayes and his twin brother when they were infants.

She used to work at Walmart but recently was not employed.

Hayes called Pollard “a great person overall, a great mother” who “never really did anybody wrong”.

He said at one point Pollard had about 10 cats.

“Every cat that she’s ever come in contact with, she has a close bond with them,” Hayes said.

Police said they found Pollard’s car parked behind Monday’s Union Restaurant in Marguerite, about 6 metres from the sinkhole.

Hunters and restaurant workers in the area said they had not noticed the manhole-size opening in the hours before Pollard disappeared, leading rescuers to speculate that the sinkhole was new.

Pollard lived in a small neighbourhood across the street from where her car and granddaughter were found, Limani said.

The young girl “nodded off in the car and woke up. Grandma never came back,” Limani said.

The child stayed in the car until two troopers rescued her.

It’s not clear what happened to Pepper.