ROME (JTA) – A large crowd marched through central Milan as a human chain to protest the defacement of a recently placed “Stumbling Stone” Holocaust memorial.

The marchers Saturday, estimated in the thousands, included Milan’s mayor and Italy’s justice minister.

Organized largely on social media, the march led from the Stumbling Stone commemorating Dante Coen to Milan’s central train station, where there is a large Holocaust memorial. Coen’s daughter, Ornella, also took part.

As they followed the route, participants were linked by a red cord, symbolizing the chain of memory.

Coen was deported to Auschwitz in 1944 and then killed at Buchenwald in 1945. The Stumbling Stone commemorating him was one of six installed in Milan, the first in the city, on January 19. It was found covered in black paint two days later.

“A quick and immediate reaction is important, so that whoever thinks to cancel testimony of this type achieves the opposite result,” Justice Minister Andrea Orlando  was quoted by local media as saying.

“Stumbling stones,” or “stolpersteine,” are individual commemorative cobblestones placed in front of the houses of people who were deported during the Holocaust. Placing them is an ongoing memorial and art project by the German artist Gunter Deming, who installs each one — nearly 60,000 in various countries since the mid-1990s.