On June 9, 2004, a nail bomb detonated in the Keupstraße attack in Mülheim, Cologne. Numerous people were injured, some of them seriously, and many stores were damaged. The attack was part of the series of murders and attacks by the "NSU", which carried out several bomb attacks throughout Germany and murdered people with an international family history.
On the 21st anniversary, there will be a commemorative event on Keupstraße, in which the NS-DOK will also take part.