From: Rabbi Moshe Sofer
To: Rabbi Yaakov Yitzchak Auerbach
A wolf fell into an enclosure of 260 sheep at night, mauled one lamb, and fled. The Chasam Sofer rules all remaining sheep are permitted, based on three grounds: the wide enclosure allowed the sheep to flee, negating any presumption of drusah; the principle of nach rugzei applies since only one lamb was seized; and as an additional measure the flock could be scattered to invoke kol d'parish me'ruba parish.
Source: Shu"t Chasam Sofer YD §57