According to Father Patrick Desbois, on   this site:

One of his interviewees was Petrivna, a Ukrainian woman, in the village of Ternivka. "The Jews", she said, "were gathered in the centre of the village and taken to a large pit on the fringes of the community. They were told to lie down, twenty at a time, and shot in the back of the head. It’s not easy to walk on bodies,"  Petrivna told the priest.

"Very calmly I asked her: ‘You had to walk on the bodies of the people who were shot?’ She replied:" ‘Yes, I had to pack them down . . . after every volley of shots.

We were three Ukrainian girls who, in our bare feet, had to pack them down, the bodies of the Jews, and throw a fine layer of sand on top of them so that other Jews could lay down.’

I [Christine Usdin] met Petrivna in Ternivka in June 2008. She is married to the only Jew who survived and shated [sic stayed?] in the village, Khaim Shtein. Khaim's daughter lives in Israel. I asked him, why he didn't go there. He answered "I was born here and I am married with an Ukrainian woman".