Rescuers contemplated the safest way Wednesday to search for a woman who apparently fell into a Pennsylvania sinkhole while looking for her lost cat, saying a crumbling old coal mine beneath the surface was complicating efforts and endangering workers.

"The search and rescue incident on Marguerite Road is still a very active scene," the Unity Township Bureau of Fire announced in a news release.Start the day smarter. Get all the news you need in your inbox each morning.

Pollard was last seen Monday evening near her home in the Marguerite community, where her car was later found parked. "It almost feels like it opened up with her standing on top of it," Limani said of the sinkhole, which rescuers believe formed suddenly.