The National September 11 Memorial & Museum (known separately as the 9/11 Memorial and 9/11 Memorial Museum) commemorate the September 11, 2001 attacks, which killed 2,977 victims, and the World Trade Center bombing of 1993, which killed six. The memorial is located at the World Trade Center site, the former location of the Twin Towers, which were destroyed during the September 11 attacks.
Wikipedia
The 70-foot high columns known as “tridents” because of their three-pronged tops, were salvaged from the wreckage of the North Tower.
Main hall of the museum, showing the last column standing at center, and the "bathtub" retaining wall around the foundation at left.
As the recovery at the World Trade Center site neared completion, the Last Column, a 58-ton, 36-foot- tall piece of welded plate steel, was removed from the site in a solemn ceremony on May 30, 2002. In the weeks that followed, recovery workers, first responders, volunteers and victims' relatives signed the column and affixed to it memorial messages, photographs, and other tributes.
This piece of steel, once part of the north façade of the North Tower, was located at the point of impact where hijacked Flight 11 pierced the building at the 93rd through the 99th floors.
North Tower Antenna
This 19.8-foot-long fragment was about one-twentieth of the 360-foot-tall transmission tower atop the North Tower. Six broadcast engineers affiliated with five television stations were working from offices on floors 104 and 110 of the North Tower on 9/11. None of the engineers survived. Transmissions for most stations failed shortly after hijacked Flight 11 pierced the North Tower. All transmissions ceased by 10:28 a.m., when the tower collapsed.
FDNY Ladder Company 3
Members of FDNY Ladder Company 3, located in Manhattan’s East Village, bravely responded to the World Trade Center on September 11, 2001. Led by decorated Captain Patrick “Paddy” John Brown, Ladder Company 3 asked a dispatcher to deploy its members to the disaster. Eleven of them, many of whom had just gone off duty after finishing their overnight shifts, entered the North Tower.
The rear mount aerial truck was parked on West Street near Vesey Street. When the North Tower collapsed, the truck was damaged beyond repair, with its entire front cab destroyed.
The 9/11 museum pavilion has a deconstructivist design, resembling a partially collapsed building (mirroring the attacks).
The Memorial’s twin reflecting pools are each nearly an acre in size and feature the largest manmade waterfalls in North America. The pools sit within the footprints where the Twin Towers once stood.
The names of every person who died in the 2001 and 1993 attacks are inscribed into bronze panels edging the Memorial pools, a powerful reminder of the largest loss of life resulting from a foreign attack on American soil and the greatest single loss of rescue personnel in American history.
One World Trade Center (also known as the Freedom Tower) is the main building of the rebuilt World Trade Center complex. The supertall structure has the same name as the North Tower of the original World Trade Center, which was completely destroyed in the terrorist attacks of September 11, 2001. The new skyscraper stands on the northwest corner of the 16-acre (6.5 ha) World Trade Center site, on the site of the original 6 World Trade Center. With a total height of 1,776 feet (541 m), its height in feet is a deliberate reference to the year when the United States Declaration of Independence was signed.