As a response to the attacks of September 11 , 2001 , Heygster contacted Bremen 's religious communities , the Deutsche Bahn railway infrastructure management subsidiary DB Netz AG , and the Bremen City Hall in 2001 and 2002 with a proposal to set up a joint sign of peace . The busy Rembertitunnel was to provide the public space for the project
attacks of September 11 , 2001
September 11 attacks
Friedenstunnel