[4][5] Another building, designed by architectural firm Walker & Gillette, was to be built on the eastern edge of the plaza, but was later cancelled due to sizing issues.
[7] Author Virginia Dajani also gave remarks on the plaza, stating that it was "considerably larger than the Piazza San Marco in Venice and infinitely less memorable".
[9] 4 World Trade Center, adjacent to the South Tower, was positioned on the southeastern edge of the plaza bounded by Liberty and Church streets.
[9] In early 1961, the plan for the original World Trade Center was released to the public, and the site was to be located along the East River.
Due to heavy backlash, that December the project was relocated to a 16-acre (700,000 sq ft; 6.5 ha) plot in Lower Manhattan.
In 1982, the Port Authority of New York and New Jersey decided to rename the plaza in honor of its former executive director,[22] Austin J. Tobin, who promoted the construction of the towers.
[28] On February 26, 1993, a van bomb planted by al-Qaeda terrorists was detonated in the underground garage directly under the plaza, killing six and injuring over 1,000.
It included an inscription with the names of the six victims of the attack, as well as a message that read: "On February 26, 1993, a bomb set by terrorists exploded below this site.
"[32] The plaza was heavily monitored, and security cameras were placed on the rooftops of surrounding buildings to deter a potential terrorist attack.
[42] Ideogram, a stainless-steel sculpture designed by James Rosati, was located on the plaza near the Marriott World Trade Center.
[43][44] On September 11, 2001, a terrorist attack unfolded at the World Trade Center site, and the plaza became an evacuation route for civilians attempting to escape the area.
[11] Firefighters directed a majority of the people who were evacuating to the mall located beneath the plaza via the lobby in the North Tower.
[48] The Sphere is the only artwork from the original World Trade Center to survive the September 11 attacks and subsequent recovery effort.
[50] 4 World Trade Center, adjacent to the South Tower, was positioned on the southeastern edge of the plaza bounded by Liberty and Church streets.