Dec. 4 (UPI) — Officials on Wednesday said a sinkhole in western Pennsylvania is now more dangerous and unstable after a missing woman reportedly fell through it while babysitting her granddaughter.

“The integrity of that mine is starting to become compromised,” Pennsylvania State Police Trooper Steve Limani said during a morning news conference.

Limani expressed hope that Elizabeth Pollard, 64, may still be alive in an air pocket after it was believed she fell in the sinkhole Monday along Marguerite Road down the way from Monday’s Union Restaurant.

“There’s been nothing that said she is not alive or she could not possibly have survived,” the trooper said. “There’s nothing that said 100% definitively it couldn’t have happened. And until that 100% happens, how could I say it’s any other way?”

Pollard left home Monday in search of her cat and was last seen at 5 p.m. EST that day in the unincorporated coal town community of Marguerite in Westmoreland County located about 40 miles southeast of Pittsburgh.

Police got a call around 1 a.m. Tuesday from a Pollard relative.

The search ultimately led to the discovery of her car at about 3 a.m. In the vehicle was Pollard’s 5-year-old granddaughter, who has since been reunited with her parents. The young girl reportedly had been in the car in freezing weather for 10 hours or more when her grandmother went missing.

About 15 to 20 feet away, police found a sinkhole about the size of a larger manhole. Limani said that they believe the sinkhole appeared as she was walking in the area.

A shoe was found in the hole.

“Let’s just say it’s a modern shoe, not something you would find in a coal mine in Marguerite in 1940,” said Pleasant Valley Volunteer Fire Company Chief John Bacha.

The sinkhole where Pollard is believed to have fallen is in an area with limestone bedrock and had almost no ground left, state police confirmed.

On Wednesday, Limani said cold water that engineers have been utilizing to flush dirt out of the mine has been causing problems with the mine’s integrity.

Limani said the hole — connected to an abandoned mine — has more than enough oxygen and is about 55 degrees warmer than above ground.

“We have to be very careful with the water issues we’ve been experiencing,” he said.

Abandoned mines and sinkholes, while rare, are uniquely a Pennsylvania problem and have been a safety hazard for decades. Limani noted the sinkhole wasn’t there before Monday. However, experts indicated the mine had been deteriorating for a long period of time.

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

A federal database showed two abandoned mines near the sinkhole where Pollard went missing which “pose the highest danger to citizens’ lives” due to land safety and other environmental concerns, according to the National Association of Abandoned Mine Land Programs.

A few years ago a 30-foot sinkhole uncovered itself in Fallowfield Township in neighboring Washington County where Pollard went missing Monday.

Pennsylvania has a long and sometimes checkered history with the dying fossil fuel industry dating back to the peak of the coal era with abandoned mines at all corners of the Keystone State.

“Sinkholes are dramatic because the land usually stays intact for a while until the underground spaces just get too big,” the U.S. Geological Survey says.

By the 1800s, Pennsylvania coal fueled America’s industrial growth and coal was the primary fuel source for western Pennsylvania’s famous steel industry, according to the state’s Department of Environmental Protection.

As of 2020, there were over 3,600 sinkholes in Pennsylvania, according to data collected by Millersville University.

In 1982, an electrician and a 35-ton crane plunged into a 288-foot abandoned mine shaft more than half filled with water around the 80-foot-wide in downtown Scranton in northeastern Pennsylvania on the opposite side of the state where Pollard went missing near an abandoned mine.

It was noteworthy in that rescuers had the option to determine if any other old adjoining tunnel to the mine would give them better access to the main shaft that hadn’t been used since the 1930s.

Years later in 2013, a 25- to 30-foot wide sinkhole roughly10- to 12-feet deep forced forced a family in the Lehigh Valley in eastern Pennsylvania to evacuate their home after a sinkhole appeared. Five years later a similar event took place in the same region when a 30 to 35 feet sinkhole likewise appeared in Cheltenham Township near Philadelphia.

The disappearance of a 64-year-old Pennsylvania woman is being investigated by state authorities, who said on Tuesday they fear she may have fallen into a sinkhole.

What Happened?

Elizabeth Pollard went missing on Monday evening after heading out to find her missing cat, Pepper, in the village of Marguerite, located about 40 miles east of Pittsburgh. The family of Pollard then called police at about 1 a.m. local time on Tuesday to say she had not been seen going out.

Pennsylvania State Police soon discovered her vehicle parked near Union Restaurant with her 5-year-old granddaughter inside, unharmed but alone.

According to trooper Steve Limani, Pollard lives in a small neighborhood across the street from where her car and granddaughter were located.

However, a sinkhole had recently opened up as emergency crews worked through the frigid night, using advanced equipment to probe the manhole-sized sinkhole.

A pole camera outfitted with a sensitive listening device revealed no signs of life, though a second inspection hinted at the presence of what may be a shoe about 30 feet below the surface.

Authorities suspect the sinkhole, likely caused by subsidence from historic coal mining in the region, opened suddenly beneath Pollard as the opening had not been seen by hunters and restaurant workers who were in the area in the hours before Pollard’s disappearance.

“It almost feels like it opened up with her standing on top of it,” Limani said.

Rescue efforts have since been intensified, with heavy machinery brought in to excavate the area.

“We’re pretty confident we are in the right place,” John Bacha, chief of the Pleasant Valley Volunteer Fire Company told Triblive. “We’re hoping there is still a void she could be in.”

How Did the Sinkhole Appear?

The sinkhole is believed to be linked to the long-abandoned Marguerite Mine, which operated until 1952 by the H.C. Frick Coke Company, according to the state’s Department of Environmental Protection. The Pittsburgh coal seam is about 20 feet below the surface in that area.

Police said sinkholes are not uncommon because of subsidence from coal mining activity in the area.

However, this incident highlights the lingering dangers of Pennsylvania’s coal mining legacy, with the state’s Department of Environmental Protection on-site to assess the area.

After the search concludes, experts from the Bureau of Abandoned Mine Reclamation will determine if mine subsidence definitively caused the sinkhole, Department of Environmental Protection spokesperson Neil Shader said.

This article includes reporting from The Associated Press.