In February 1984, soldiers of the Kenya Army mounted a security operation around Wajir in Kenya's North Eastern Province. Having rounded-up all Somali men of the Degodia clan, as many as 5000 were taken to the Wagalla airstrip for interrogation. This was part of the policy of ‘collective punishment’ – a conscious act of state violence against its own citizens. After four days of interrogations at Wagalla, several hundred Degodia lay dead: whether 500 died, or 1000, or more is unknown, but the incident stands as the worst atrocity in Kenya's modern history. This article recounts what is known about the massacre from witness and survivor testimony, putting this together with documentary evidence recently revealed through the Truth, Justice and Reconciliation Commission (TJRC) and setting the analysis in the wider context of Kenya's treatment of the peoples of its ‘forgotten north’. The conclusion summarises the findings of Kenya's TJRC on Wagalla, and comments on the recent construction of a monument to commemorate the massacre, opened at Wajir on 14 February 2014.