(CNN) -- Each year around September 11, CNN Hero Jeff Parness and his volunteers go to a disaster-stricken community to help them rebuild.
The efforts are part of New York Says Thank You, an organization Parness created to honor the support that other cities provided after the 2001 terrorist attacks.
The volunteer group continues to grow because many of the people it helps go on to "pay it forward" and participate in the next year's rebuilding project. Since 2004, nearly 10,000 people nationwide have participated in projects organized by Parness.
CNN's Kathleen Toner recently spoke with Parness about his group's plans for the 10th anniversary of 9/11, which includes the final restoration of the National 9/11 Flag.
Kathleen Toner: Where did your group decide to go for this year's build?
Jeff Parness: (In April) we were watching the news and there were tornadoes that came through northwest Georgia. In the middle of this news clip, there's this beautiful older woman in a destroyed barn with all of her animals.
This lovely woman, Susan Littlejohn, lived in the barn with 65 animals that she had rescued (and) used as therapeutic companions for disabled children and seniors. ... So we decided (that) we're going to bring about 300 volunteers from around the country and do a "barn raising" in Ellijay, Georgia.
Toner: How did it go?
Parness: It's hard to compare projects, but in terms of the numbers of people that we got and who turned out from the local community, it was one of most successful events we've ever done. So many local folks came with their families. I think we had close to 2,000 people.
We finished about 80 percent of the barn, but the real metric we used to measure success was how many people we drew from the community to teach them about Susan's Build An Ark animal rescue program. ... She's dedicated her life and sacrificed so much for caring for animals and using them as a way to inspire other people and inspire volunteerism. We thought that if she got one more volunteer or one more dollar, it was worth it.
That weekend we raised over $15,000 for her, and all kinds of people were volunteering to donate their talents and help with bookkeeping, et cetera. ... At the end of the day, the community of Ellijay realized Susan and her work are very special.
Toner: What are your plans for 9/11 this year?
Parness: Normally we always do one main building project before 9/11, but for various reasons we did this year's project at the end of July. Now it looks like we've got around 100 people who are going to be gathering in Joplin, Missouri, from September 8 to 11.
We're going to be doing two main things. We're painting 3,000 "Stars of Hope." This is a project where kids paint inspirational messages of hope and they're planted in all of the corners of the town that were wiped out when the tornado hit on May 22. There are more than 600 intersections that aren't there anymore. When we leave, they are going to be transformed. Everywhere you look there will be these colorful, inspirational messages.
The second thing we're doing is really significant: the National 9/11 Flag is going to finish its tour in Joplin.
Toner: What is the National 9/11 Flag?
Parness: One of the greatest projects that's come out of New York Says Thank You is we wound up being custodians for what's now known as the National 9/11 Flag, which was one of the largest American flags to survive ground zero. The flag is 20 feet high and 30.5 feet wide.
The pieces of the flag (were brought) to Greensburg, Kansas, when we were helping to rebuild there (after a 2007 tornado).
While we were out building this 14,000-square-foot 4-H barn, all the ladies in the senior citizens' center stitched the flag back together. And where pieces of the original flag were missing, they sewed in American flags that survived the Greensburg tornado. (It) literally stitched together our two histories, both tragedy and triumph, seven years later.
After the initial restoration (see photo at left), the flag looked like a beautiful patchwork quilt. But for the past couple of years, we've taken the flag around the country to all 50 states to let local service heroes stitch it back to its original 13-stripe format using pieces of American flags that were being retired. The idea was to (finish it) for this 10th year anniversary of 9/11.
It's going to become part of the permanent collection of the 9/11 Memorial Museum that's being built at the World Trade Center.
Toner: You really brought it to all 50 states?
Parness: Yep. We had a stitching ceremony in Hawaii on Pearl Harbor Day and had World War II veterans stitch the flag. We brought it to Mount Rushmore. ... There have been so many extraordinary locations and people. We've had 25,000 people so far stitch the flag.
Toner: What will you be doing with the flag in Joplin on 9/11?
Parness: On the morning of the 11th, the National 9/11 Flag will be displayed in a silent tribute at the exact moment that the north and south towers fell. It will be held by Joplin first responders, local residents and disaster survivors from across the United States.
The flag will then serve as the backdrop for a 9/11 Memorial Service. And following that, all of the folks in Joplin will be invited to place the final stitches in the flag using fabric that survived the Joplin tornado.
It's about bringing people together and giving them the ability to put a stitch in and connect the stories of all of us. ... The symbolism is going to be super powerful. 9/11 didn't just happen in New York or Washington or Shanksville, Pennsylvania -- it happened in America. There are always going to be tragedies in our country like tornadoes. This says we're all going to be there for each other.
Read the full story on CNN Hero Jeff Parness:
'Paying it forward' after 9/11