The article explores how a notorious case of Second World War atrocities in Ukraine – the Babi Yar massacres of 1941-1943 – is represented and interpreted on Wikipedia. Using qualitative content analysis, it examines what frames and content features are used in different language versions of Wikipedia to transcribe the traumatic narrative of Babi Yar as an online encyclopedia entry. It also investigates how these frames are constructed by scrutinising the process of collaborative frame-building on discussion pages of Wikipedia and exploring how Wikipedia users employ different power play strategies to promote their vision of the events at Babi Yar.