A woman who fell into a hole in the ground while searching for her cat is not expected to be found alive

Efforts to locate a Pennsylvania grandmother who appears to have fallen through a hole in the ground into a decades-old mine shaft while searching for her cat have most likely shifted from a rescue operation to a recovery mission, authorities said Wednesday.

Pennsylvania State Police Trooper Steve Limani told reporters that oxygen levels in the shaft, which he estimated was at least 30 feet deep, were decreasing and there was no sign of life.

“Unless it’s a miracle, it’s most likely a recovery,” he said.

He said there was little doubt that 64-year-old Elizabeth Pollard fell through what he called a thin piece of land in Unity Township, about 40 miles southeast of Pittsburgh.

Authorities said she was last seen Monday around 5 p.m. A relative called 911 hours later and reported her missing, Limani said.

State troopers discovered her car parked near a restaurant with her five-year-old granddaughter inside. The granddaughter was in good condition despite the freezing temperatures, he said.

Using cameras, authorities saw what appeared to be a modern-looking shoe at the mine on Tuesday but had no contact with Pollard.

Limani said authorities would change their approach to searching for Pollard because of the fragile state of the mine.

Rescue workers tried to vacuum up dirt, debris and rocks, he said, and they used water to soften the area.

But faced with the possibility of a collapse, they now plan to dig a huge hole to access the area.

“We’re not giving up,” he said. “We will continue to work on it.”