The Site in Dates
The towers, 1972 to 2001
The North Tower, 1 World Trade Center, rose 1,368 feet and the South Tower, 2 World Trade Center, 1,362 feet. They were completed in 1972 and 1973, and at completion they were the tallest buildings in the world. The height page compares them with the tower that stands today.
26 February 1993
A bomb in the garage beneath the towers killed six people. Their names are on the memorial with the 2,977 of 2001, which is why the parapets carry 2,983 names.
11 September 2001
2,977 people were killed in the attacks in New York, at the Pentagon and on Flight 93; 2,753 of them in New York. The first impact was at 8:46 am and the second collapse at 10:28 am, the 102 minutes the Oculus skylight now opens for each anniversary.
The recovery, to 30 May 2002
Recovery work continued through the winter. On 30 May 2002 the Last Column, the final piece of steel, left the site and the recovery ended. The column now stands in Foundation Hall. The Tribute in Light had first been lit on 11 March 2002, six months after the attacks; the Tribute in Light page covers it.
Designing the memorial, 2004 to 2011
In January 2004 “Reflecting Absence” by architect Michael Arad with landscape architect Peter Walker was chosen from 5,201 entries. The Survivor Tree, found alive in the rubble in October 2001, returned to the plaza in December 2010. The memorial was dedicated for families on 11 September 2011 and opened to the public on 12 September 2011. The pools page explains the design.
The museum, 2014
The museum was dedicated on 15 May 2014 and opened to the public on 21 May 2014. On 10 May 2014 the unidentified remains were moved to a repository at bedrock, described plainly on the repository page. The museum welcomed 23 million visitors in its first ten years.
Above and around, 2015 to 2019
One World Observatory opened on 28 May 2015 on floors 100 to 102 of One World Trade Center. The Oculus opened on 3 March 2016. The Memorial Glade, for the rescue and recovery workers and others who fell ill or died from exposure after the attacks, was dedicated on 30 May 2019.
The Last Column, the slurry wall and the Survivors’ Stairs are the recovery-era objects visible today; all three are inside the museum, on the timed ticket.
Frequently asked questions
When did the 9/11 Memorial open?
It was dedicated on 11 September 2011 and opened to the public on 12 September 2011.
When did the 9/11 Museum open?
On 21 May 2014, six days after its dedication. The inside page describes it.
How many people died on 11 September 2001?
2,977, of whom 2,753 were in New York. With the six killed in 1993, the memorial carries 2,983 names; see how many names.
When was the Last Column removed?
On 30 May 2002, which marked the end of the recovery. It stands in Foundation Hall today.