ST. BERNARD PARISH, Louisiana (CNN) -- This year, the anniversary of Hurricane Katrina will hold new meaning for Tina Caserta and her family.
Liz McCartney runs the St. Bernard Project, which helps families rebuild in a parish hit by Hurricane Katrina.
Like countless other residents from St. Bernard Parish, a community just east of New Orleans, Caserta lost everything in the storm. She had lived there since she was 12, married and raised her three sons there and even lived on the same street as her husband's family.
"We had nothing to salvage ... nothing," said Caserta, 41.
She returned to her community just two months after Katrina, but she and her family have been enduring the challenges of moving from one form of FEMA housing to another ever since. When the family home she had been fighting to return to was condemned and torn down earlier this year, it was the final straw for Caserta.
"I was spiraling down," she said, choking up. "I was totally hopeless."
That's when she found Liz McCartney and her nonprofit St. Bernard Project. In the past three years, McCartney and her team have helped more than 230 families rebuild and move back into their homes.
At the fourth anniversary of Katrina, Caserta and her family finally see a light at the end of the tunnel.
"The day that St. Bernard Project called and told me they [would] be able to help my family rebuild, that was the first day I felt like I could breathe," recalled Caserta. "They gave my family hope."
McCartney, 37, was honored last November as the CNN Hero of the Year for her efforts in St. Bernard Parish. She said the CNN Heroes award has had an incredible impact on the effectiveness of her St. Bernard Project, which she co-founded with Zack Rosenberg.
More than 5,000 new volunteers have joined their cause, bringing their total to date to 15,000; and the group has raised more than $300,000 from new funding sources.
"We're rebuilding homes more efficiently than ever before," McCartney said. But her ultimate goal remains the same: "We want to work ourselves out of a job." Read more about CNN Hero Liz McCartney and her efforts in St. Bernard Parish
For McCartney, that means helping to address the housing needs of thousands of families still living in Federal Emergency Management Agency trailers or temporary housing. The St. Bernard Project recently expanded to rebuild homes in New Orleans and opened a center for wellness and mental health, offering residents one-on-one and group counseling, among other clinical services.
A combination of the heartbreaking stories of continued suffering and the speed at which her group can get those families back to normal, said McCartney, "re-energizes me and everyone on our staff about working harder and working smarter to get the job done."
To that end, this anniversary will be "business as usual" for the group, she said. Beginning Friday, it will hold a 24-hour build. McCartney predicts at least 120 volunteers from all over the country will each work an eight-hour shift to help build four homes.
"We get out there and show how much work can get done in a 24-hour period, which is pretty significant," McCartney said. Watch how McCartney's organization helped one St. Bernard resident move home
Caserta and her 17-year-old son signed up to volunteer with the graveyard shift because "it will give us a chance to help another family out and give them the hope that I feel."
The organization also plans to launch a yearlong campaign called "4 NOLA," which will include a number of fundraisers and events throughout the country.
"It focuses on the positive, promotes the progress we've made, but shows that we still have a ways to go," McCartney said. "We've seen thousands of people who are ready, willing and able to respond to the needs of their fellow Americans. It's our job to continue reminding them that the need here is great." Watch McCartney describe her turning point while volunteering in New Orleans
Today, McCartney is optimistic. And thanks to her organization's efforts to bring the community back, Caserta and many other St. Bernard Parish families are optimistic, too.
"This is going to be the first time that I can actually go through the anniversary with tears of joy, not tears of sorrow," Caserta said. "Every day I see the progress [of] these volunteers, it makes me able to accept that date and the reality of what it's done to my family. Without people like Liz, people like me wouldn't have that opportunity to come home."