A just-released time-lapse video shows the incredible undertaking of rebuilding Ground Zero after the 9/11 attacks. 

The two-minute video has already been watched on YouTube more than 1.2 million times.

The video was shot by EarthCam, whose founder posted the following message with the video.

It's been a heroic undertaking to rebuild downtown New York City after the September 11, 2001 terrorist attacks. Within days of this national tragedy, I personally installed a camera to webcast the rescue and recovery for the families, and the world, to see the brave determination of first responders. As the recovery effort continued, we installed more cameras to document the rebuilding and construction of the site. This commemorative time-lapse honors the victims of 9/11 and is dedicated to their families and friends, with special gratitude to the first responders and the steadfast construction teams.

A super hardworking team at EarthCam, who I am so proud to work with, spent countless hours keeping the many webcams at the World Trade Center active for 4,617 days (and counting). This unprecedented effort provided our in-house editors with over 1 million images to choose from when creating this two-and-a-half minute video, as well as our other commemorative World Trade Center movies.

We at EarthCam are committed to continuing this photographic documentation to educate future generations and have donated all the images as well as the original camera to the 9/11 Memorial Museum.

I hope this time-lapse serves as a way to recognize that for the 10 years of construction, there was constant progress made to rebuild these important 16 acres of America.

Brian Cury

It took more than a decade for the site to be transformed into the 9/11 Memorial, which was built in the shadow of the 104-story One World Trade Center.

Watch the awesome footage above.