UNITY, Pa. (AP) — A sinkhole where a Pennsylvania woman fell to her death last month is being filled with hundreds of cubic yards of grout in a bid to stabilize the site.

The work in the village of Marguerite, about 40 miles east of Pittsburgh, started just days after emergency responders found the remains of 64-year-old Elizabeth Pollard on Dec. 6. She had gone missing four days before while searching for her cat. The sinkhole was near a restaurant about half a mile from her home.

Crews have since pumped more than 3,300 cubic yards of grout into the site, the Pittsburgh-Tribune-Review reported, but it’s not yet known when the work will be completed. The work was put on hold this week due to snow and extremely cold temperatures, but officials hope to resume working soon.

State environmental officials have said the crews are digging between 12 and 16 boreholes strategically placed across the property. Each is being pumped with a cement-like grout mixture that will slowly spread over a roughly 25-foot area as it hardens, forming wide pillars to support the earth above.

Officials have said the sinkhole apparently began as a manhole-sized gap. It may have only recently opened above where coal was mined until about 70 years ago. Hunters and restaurant workers in the area in the hours before Pollard’s disappearance told police they hadn’t noticed the sinkhole.