Michael Thompson's house hummed with noise Tuesday, but for once it wasn't a family of birds chirping on the roof.
These sounds came from a dozen teenagers pulling away rotted beams and hammering new shingles into place.
Michael and his wife, Torra, are getting a visit this week from the World Changers, a program sponsored by the Southern Baptist Convention that sends teenagers on summer mission trips.
By Friday, the teens will finish a new roof at the Thompsons' house on Harrison Street -- without the crevice on one side where birds built a nest. A feathery friend would occasionally fall into the living room and flutter around until someone shooed it out.
"They would come visit quite often," Torra Thompson said. "You could hear them singing."
Over the past decade, more than 150 seniors and low-income homeowners in Rock Hill have gotten similar help.
"That old roof held as long as it could," said Michael Thompson, who works two jobs and underwent triple-bypass surgery last month. "They just stepped right in and really helped us."
The teen volunteers got a special treat Tuesday night. They visited the Catawba Indian Nation reservation to eat Indian tacos -- fried bread, ground beef and assorted toppings -- and watch a Native American powwow with drums, dance and storytelling.
Just before climbing into a van with "Honk if you love Jesus" spraypainted on the window, Tiffany Blackburn explained what keeps bringing her back to the World Changers. This is her sixth trip with the group.
"We know we're doing it for the Lord," she said. "It gets better every year."