This story was originally published by High Country News and is reproduced here as part of the Climate Desk collaboration.

The night of Nov. 20 was brutal for the activists protesting the Dakota Access Pipeline near North Dakota’s Standing Rock Sioux Reservation. As temperatures dipped below freezing, some 400 faced off with police over a bridge closed by the Morton County Sheriff’s department to block access to a pipeline construction site.

Videos show police spraying the activists with frigid water and firing rubber bullets. Twenty-six people were hospitalized, including 21-year-old Sophia Wilansky, who says her arm was nearly blown off by a concussion grenade thrown by police. The Morton County Sheriff denies using such grenades.