-- > A memorial called '' Reflecting Absence '' honors the victims of the September 11 attacks and the 1993 World Trade Center bombing . The memorial , designed by Peter Walker and Israeli-American architect Michael Arad , consists of a field of trees interrupted by the footprints of the twin towers . Pools of water fill the footprints , underneath which sits a memorial space whose walls bear the names of the victims . The slurry wall , which holds back the Hudson River in the west and was an integral part of Libeskind 's proposal , remains exposed . Walker and Arad were selected from more than 5,000 entrants in the World Trade Center Site Memorial Competition in January 2004
1993 World Trade Center bombing
1993 World Trade Center bombing
World Trade Center (2001–present)