Search continues near Pennsylvania grandmother Elizabeth Pollard sinkhole

A search for a grandmother is believed to have fallen into a massive sinkhole Wednesday as Pennsylvania officials encountered unstable parts of an abandoned mine below the sinkhole.

Elizabeth Pollard, 64, was searching for her lost cat Pepper when she disappeared Margaret, Pennsylvania, On December 2, she stopped by a local restaurant with her five-year-old granddaughter in the car at the time.

Marguerite, a sparsely populated village, is prone to sinkholes due to past mining activity. Authorities believe Pollard has fallen into the past Marguerite mine, It last operated in 1952.

Crews determined that parts of the abandoned coal mine were too unstable to safely search for Pollard but expressed hope that the 64-year-old grandmother would be found alive.

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On Wednesday, Pleasant Unity Fire Chief John Bacha said crews arrived at the location where Pollard is believed to have fallen, but found no sign of him.

Operations officer Bacha said the mud may have moved her elsewhere in the mine.

“We got, you know, where we wanted, where we thought she was. We went to that location,” Bacha explained. “What happened at that time, I don’t know, maybe the slush pushed her in one direction. There were so many different seams, shafts all together in that mine.”

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Authorities are hopeful that Pollard is still alive, although conditions are mixed. Although overnight temperatures dipped to freezing earlier this week, officials said parts of the sinkhole still had plenty of oxygen.

“All the oxygen levels are perfect,” Bacha told KDKA on Tuesday. “No carbon monoxide, no explosive gases, nothing.”

“At the moment the weather is perfect, so we still have some hope and we’ll be able to get there.”

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Authorities are actively investigating the incident. No additional details are known at this time.

The Associated Press contributed to this report.