UNITY TOWNSHIP (AP) — The search for a woman who allegedly fell into a sinkhole in western Pennsylvania has become a recovery effort after two perilous days of digging through mud and rock that produced no signs of life, authorities announced Wednesday.

The team tasked with finding Elizabeth Pollard, 64, packed up Wednesday evening and planned to return Thursday morning.

Pennsylvania State Police spokesman Trooper Steve Limani said at a news conference that authorities no longer believe they will find Pollard alive, but that work to find her remains continues. continues.

“We haven’t had any signs of any life form or anything” that would make rescuers think they should “keep trying to push and rush and push the limits, to be aggressive with the potential risk of harming other people,” Limani said. .

He noted that oxygen levels underground 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 5-year-old granddaughter inside was found about two hours later near what is believed to be a freshly opened sinkhole above a mine closed and in ruins for a long time.

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

Limani praised the crews who went to the abandoned mine to help remove materials needed to search for Pollard in Marguerite, about 40 miles east of Pittsburgh.

“They came out from head to toe covered in mud, exhausted. And while they were being stopped, the next group was coming. And there was one after another,” Limani said.

Authorities had earlier said the roof of the mine had collapsed in several places and was no longer stable.

“We got to, you know, where we wanted, where we thought she was. We went to that location,” Pleasant Unity Fire Chief John Bacha, who is in charge of incident operations, said earlier Wednesday. “What happened then, I don’t know, maybe the mud pushed her in one direction. There were several different veins in this mine, shafts that all came together where this happened.

Searchers used electronic devices and cameras while surface excavations continued with the use of heavy equipment, Bacha said. In the coming days, they plan to significantly widen the surface hole, with winter weather forecast in the area.

Geological engineer Paul Santi said Pollard’s chances of survival if she slipped into the sinkhole were “pretty low.”

“There are a lot of problems,” said Santi, a professor at the Colorado School of Mines. “There are rocks and dirt and things that could have buried him. There is water that could have filled it. You have to go through rescue. But I would be surprised if she came out well… she would have to not have been killed by the fall, she would not have been killed by the rock, there would have to be an air pocket and that she is able to survive it.

Sinkholes occur in the area due to subsidence from coal mining activity. Rescuers used water to demolish and remove clay and dirt from the mine, which has been closed since the 1950s.