Rescuers were desperately searching for a grandmother who they believe fell into a gaping sinkhole — holding out hope of finding her despite the difficult rescue conditions.

The search and rescue mission has, so far, not turned up any signs of Elizabeth Pollard in Unity Township, Pennsylvania State Police said Tuesday.

“Hopefully she’s in an air pocket,” authorities said, noting that there have been incidents in the region where people have survived similar situations in underground mines. “This is a rescue to me until something says that it’s not.”

The sinkhole is believed to be tied to an abandoned coal mine, officials said.

Search crews have been able to make entry into the mine area, Trooper Steve Limani told reporters at the scene Tuesday evening. The search will continue as long as needed pending any safety concerns, he said.

Rescue teams from nearby areas have joined forces, swapping shifts to keep the effort going. Oxygen tankers are being delivered regularly to supply the mine shaft, and crews have made progress entering the underground area.

The conditions are tough, with clay-like soil making it difficult to dig, but rescuers remain determined. “We’re doing everything we can, and no one is giving up,” said Liman

He added, “It’s heartbreaking for her family and everyone here. But we’re not stopping. We’re all hoping for a miracle.”

Pollard was reported missing by a family member shortly before 1 a.m. Tuesday, Limani said at an earlier press conference Tuesday.

Pollard was last seen around 5 p.m. Monday, Limani said. The family member said Pollard had gone out to look for her cat Monday afternoon but has not been heard from since, he said.

Pollard’s vehicle was located shortly before 3 a.m. Tuesday with her 5-year-old granddaughter inside, though Pollard was nowhere to be seen, police said.

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

While searching for Pollard in the area, troopers found an apparent sinkhole with an opening about the “size of a manhole” 15 to 20 feet away from the vehicle, Limani said.

Emergency responders were called to the scene in what is currently being considered a rescue mission, authorities said. Local firefighters, a technical rescue team and the state’s Bureau of Mine Safety are among those working alongside an excavation team to remove dirt to access the sinkhole, Limani said.

The current evidence points toward Pollard being in the sinkhole, Limani said.

“We don’t feel a reason that we should be looking elsewhere,” he said.

The sinkhole appears to have been created during the time that Pollard was walking around, Limani said, noting that there is no evidence that the hole was there before she started looking for her cat.

A camera inserted into the opening of the sinkhole showed a “big void, and it was all different depths,” Marguerite Fire Chief Scot Graham told reporters during the earlier press briefing.

“The process is long and it is tedious,” Graham said.

A camera did not pick up any sounds, though authorities did see a “modern-type” shoe in the sinkhole, according to Pleasant Unity Fire Chief John Bacha.

The mine last operated in 1952, according to the state’s Department of Environmental Protection. The depth to the coal seam in this area is approximately 20 feet, a department spokesperson said.

Once the scene is clear, the department will investigate the site “to determine if this issue is the result of historic mine subsidence,” the spokesperson said.

Pollard’s granddaughter is safe, despite the cold temperatures overnight, and is currently with her parents, Limani said.

The family is asking for privacy at this time and is hoping for “good news,” he said.

“We need to get a little bit lucky,” Limani said. “We’re going to do everything we can.”

ABC News’ Alexandra Faul and Jason Volack contributed to this report.

A growing number of senators have privately signaled that they are not inclined to vote to confirm Pete Hegseth as President-elect Donald Trump’s next defense secretary, leading Trump’s advisers to begin discussing who may be a viable replacement, sources familiar with the matter told ABC News.

Sources tell ABC News that at least six senators have privately indicated that they don’t intend to vote for Hegseth amid the growing allegations about his mistreatment of women.

While Trump and his advisers have privately said the president-elect backs Hegseth and wants him to “keep fighting,” sources familiar with private discussions tell ABC News that a growing list of replacements is emerging to replace him. Those include Iowa Sen. Joni Ernst, Florida Gov. Ron DeSantis, Tennessee Sen. Bill Hagerty and Florida Rep. Mike Waltz, whom Trump has already tapped to be national security adviser.

Sources close to DeSantis say he has expressed interest in the role. He was seen today with Trump attending a memorial service for three Palm Beach County sheriff’s deputies in West Palm Beach, who were killed in a crash last month.

Reached by ABC News, a spokesperson for the Trump transition team declined to comment.

Hegseth was back on Capitol Hill Tuesday looking to shore up support as he fends off the allegations of misconduct and sexual impropriety.

The visit came after a report in The New Yorker that Hegseth was forced to step down from two veteran nonprofit groups — Veterans for Freedom and Concerned Veterans for America — amid accusations of financial mismanagement, sexist behavior and other disqualifying behavior.

ABC News has not independently confirmed the magazine’s account. Hegseth’s attorney, Tim Parlatore, told The New Yorker the claims were “outlandish.”

Two days after President Joe Biden issued a blanket pardon to his son Hunter Biden, the federal judge overseeing the younger Biden’s tax charges in California slammed the president’s characterization of the case as an improper attempt to “rewrite history.”

U.S. Judge Mark Scarsi — who was appointed by Donald Trump — took aim at President Biden’s suggestion that “no reasonable person” would find the charging decisions against his son fair, noting that the “president’s own attorney general and Department of Justice” oversaw the case.

“In the President’s estimation,” Scarsi continued, “this legion of federal civil servants, the undersigned included, are unreasonable people.”

“The Constitution provides the President with broad authority to grant reprieves and pardons for offenses against the United States … but nowhere does the Constitution give the President the authority to rewrite history,” Scarsi said.

However, Scarsi concluded that the intent of the pardon was clear enough – even if the language in the pardon itself was potentially “unconstitutional” – and agreed to terminate the case once the court received the appropriate records from the Office of the Pardon Attorney.

“The Court directs the Clerk to comply with court procedures for effecting a grant of clemency once the pardon is formally received, which will result in the termination of the case,” he wrote.

Hunter Biden’s federal gun case in Delaware was terminated Tuesday morning by the judge overseeing that case.

“In the absence of binding precedent” for a case that had yet to reach sentencing, “all proceedings in this case are hereby terminated,” U.S. District Judge Maryellen Noreika wrote in a brief docket entry Tuesday.

In a court filing Monday, prosecutors had urged Noreika to terminate the case instead of dismissing the indictment, in order to allow the record of the case to continue to exist.

Prosecutors in special counsel David Weiss’ office, who brought both the gun case and separate tax-related charges against Hunter Biden, on Monday made a similar filing to the federal judge overseeing Hunter Biden’s tax case in California.

President Biden on Sunday issued a blanket pardon to his son, who earlier this year was convicted on federal gun charges and pleaded guilty to tax-related charges, and was scheduled to be sentenced in both cases later this month.

Early predictors of dementia are emerging as critical tools for guiding health and lifestyle decisions long before symptoms appear.

The Health and Retirement Study, which looked at more than two decades of data from over 45,000 older adults in the United States, suggested that lifestyle, genetics and other factors at 60 years old can help predict brain health at 80.

“Our research confirmed that factors like low cognitive test scores and poor general health in one’s 60s are strong predictors of dementia later in life,” said Peter Hudomiet, the PhD-level researcher and economist at the RAND Corporation, who led the study, told ABC News.

“We also uncovered some surprising insights, such as the significant protective effect of education, particularly having a high school diploma, and the increased risk associated with living in the South,” he added.

Among the study’s findings, younger seniors who engaged in physical activity and mentally stimulating hobbies appeared to have a lower risk of cognitive decline. Conversely, those who led sedentary lifestyles and those who had few mentally stimulating interests to occupy their time were more likely to develop dementia by age 80. Excessive alcohol use was also bad for the brain, the study found.

“Lifestyle factors like minimal exercise, extreme obesity, and both excessive and no alcohol consumption also emerged as important contributors. These findings highlight the complex interplay of behavioral, social, and genetic factors in dementia risk,” Hudomiet said.

Chronic health conditions including diabetes, obesity and stroke by the age of 60 were strongly linked to a higher chance of dementia later in life, according to the study.

Some groups were higher at risks than others, such as those born in a Southern state. Black and Hispanic people were also at higher risk as well, possibly because they lacked access to health care, the study said.

“We do see very large differences by socioeconomic status, measured in various ways — for example, using education, income, wealth, and race. People with lower education, less income, less wealth, and racial minorities all face higher chances of dementia,” Hudomiet said. “However, when we control for education and income, the racial disparities disappear, suggesting that the differences are related to socioeconomic factors.”

This is good news, Hudomiet said, because it means addressing disparities could help close these gaps for high-risk groups.

While genetics and age can’t be changed, the study emphasized that many other risk factors can be proactively addressed. For instance, getting regular exercise, finding a hobby, staying socially active and managing chronic conditions all may help keep the brain sharp. Limiting alcohol consumption, eating a healthy diet and getting good sleep all helped mitigate risk as well.

Kristine Yaffe, MD, professor of psychiatry, neurology, and epidemiology at the University of California at San Francisco said she thought the study added some impressive evidence for real strategies that help stave off dementia.

“The findings underscore the importance of genetics, behaviors, and lifestyle factors. In particular, they highlight critical considerations for promoting brain health across the life course,” she said.

She urged people to start thinking about their brain health early.

“We need to increasingly think about ways to promote brain health, just as we focus on promoting cardiovascular health. This is something we should consider across every stage of life, not just when we’re older and start worrying about memory,” she said.

Despite its comprehensive findings, the study doesn’t prove that changing lifestyle behaviors can help prevent dementia, only that they are associated with a lower risk of the disease. The authors call for further research to explore targeted interventions for a wider variety of people.

An estimated 6.9 million Americans are living with dementia, according to the National Institutes of Health. Those numbers will double by 2060, the Centers for Disease Control and Prevention projects.

Neil C. Bhavsar is an emergency medicine resident physician with New York Presbyterian, Columbia/Cornell and a member of the ABC News Medical Unit.