Rescue workers search a sinkhole for Elizabeth Pollard, who disappeared while looking for her cat, in Marguerite, Pennsylvania, Tuesday. (Photo credit: Gene J. Puskar/AP via CNN Newsource)

(CNN) — Rescuers are searching for a missing Pennsylvania grandmother who is believed to have fallen deep into a sinkhole while searching for her cat with her young granddaughter, authorities said.

Police received a phone call around 1 a.m. Tuesday from a relative of Elizabeth Pollard, who said the 64-year-old had left to look for her cat Monday afternoon and had not been heard from since, Trooper Steve Limani of the Pennsylvania State Police in Greensburg said in a news conference Tuesday.

Pollard was last seen around 5 p.m. Monday in Marguerite, an unincorporated area of Unity Township, Limani said, in part of southwestern Pennsylvania dotted with old coal mines.

During their search, police discovered Pollard’s vehicle parked near a restaurant with her 5-year-old granddaughter inside – and a fresh, deep sinkhole just steps away.

“We at that point in time realized that this could be a very bad situation,” Limani said.

Rescuers hope Pollard is still alive in an air pocket. The hole has plenty of oxygen and is warmer than the temperatures above ground, officials said.

Pollard’s granddaughter was unharmed, despite being in the car for nearly 12 hours in below-freezing temperatures, Limani said.

The girl is now with her parents and wasn’t able to give police any details about what happened, Limani said. “She was just a 5-year-old girl that was waiting in the car for her grandmother to come back.”

The sinkhole, which was about 15 to 20 feet from Pollard’s vehicle, appears to be about the size of a manhole on the surface but gets much wider below ground, making search and rescue efforts challenging, Limani said.

The sinkhole likely appeared at some point Monday, officials said. “That hole wasn’t there earlier in the day … It’s close enough to the building that somebody would have seen it,” Limani said.

Pleasant Valley Volunteer Fire Company Chief John Bacha said he took an initial look in the hole using a ladder and a harness but did not spot Pollard.

“You couldn’t even get close enough to the hole because of the way it was undermined,” Bacha said.

“A lot of the little villages around here are old coal patch towns,” Bacha added. “Very common to find a lot of mines in these areas, obviously a concern to have these mine subsidence issues.”

Specialized rescue crews and excavation teams were brought in to help with the search, officials said.

While no sounds have been picked up by monitoring equipment, the rescue teams spotted a shoe in the sinkhole using a camera, Bacha said.

“Let’s just say it’s a modern shoe, not something you would find in a coal mine in Marguerite in 1940.”

Search efforts will continue overnight, Limani said.

“Let’s be honest, we need to get a little bit lucky.”

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