An unknown vandal has destroyed Germany’s last remaining Banksy mural, Süddeutsche Zeitung reports. The elusive street artist sprayed the stencil Bomb Hugger, which depicts a little girl embracing a bomb, on a concrete pillar in Hamburg’s city center in 2003. A local arts foundation installed a protective plexiglass covering over it in 2011.

Not discouraged in the slightest by the plexiglass covering, the perpetrator sprayed the words “GRAFFITI” above the piece, adding a heavy underline which dripped underneath the protective glass to deface the artwork. The case is being treated as an act of deliberate vandalism based on the “dripping” technique used.

The exact time of the defacement remains unknown, although reports on Twitter, which surfaced on February 10 suggest that the damage occurred approximately two weeks ago. The blue spray-painted letters have since been removed.

So far Hamburg Police are not investigating the incident because they have not received any criminal complaints. Responding to an inquiry by Süddeutsche Zeitung, Hamburg Police reportedly told the German daily that the artwork was undamaged by the incident, although photo evidence clearly suggests otherwise.

According to Rene Spiegelberger, founder of the Spiegelberger Foundation, which installed the protective plexiglass cover over the work, the foundation is currently exploring various avenues to enable the restoration and improve the protection of the work.

Surprisingly, Hamburg’s residents have barely noticed or reacted to the incident. The northern German city has a vibrant street art scene and was the stomping ground of the late graffiti legend Oz. (see German Graffiti Legend Oz Killed by Train, and German Green Party Campaigns to Save Oz’s Graffiti).

Elsewhere, Banksy’s Spy Booth mural, which popped up in the English town of Cheltenham in 2014, has been granted listed protection by the local government (see Banksy’s Spy Booth Mural Cherished and Perserved in Cheltenham).