It pays tribute to the resilience of 9/11 families, and the loved ones they lost.
The newly published book, "Legacy Letters: Messages of Life and Hope from 9/11 Family Members," is a compelling collection of letters, compiled by Tuesday's Children, an organization that provides support for the families of 9/11 victims and others impacted by global terrorism.
The touching letters were written by those who were left behind.
Many of them would give anything to have just one more moment to tell a father, a mother, a brother, a sister - how much they love them.
Now, some got the chance to do just that. Watch the video above for some of their stories.
For more on Tuesday's Children, visit TuesdaysChildren.org