Rhonda Williams and her three sons checked into an emergency shelter in Loudoun County 11 years ago.

What a difference a decade makes.

Now, the three brothers -- Victor, 20, Joseph, 17, and Michael, 15 -- are out of the shelter and are giving back. They have helped tutor younger children, built a peace park behind a mosque, cleaned up streets, and collected trash from the Anacostia River.

This week, they're headed to Costa Rica with the International Relief Friendship Foundation to renovate shelters and dining facilities.

"I always want to continue service work," said Joseph, who is attending the University of Virginia. "[It] keeps you focused on what's important."

Indeed, for the Williams brothers, the volunteer work is nothing out of the ordinary -- aside from it being their first trip abroad.

"You never know how much helping out a little bit [will help]," Michael said. "What goes around comes around."

But the boys remain grounded; for them, growing up at the shelter was simply their reality.

"You never realize how different you are until people tell you," Joseph said. "Change is the only constant in life."

Victor, 20, attends Bridgewater College in Virginia and occasionally substitute teaches in Loudoun. The eldest of the three, he made sure to keep their efforts in perspective.

"There's so many people that do so much more than we do," he said.

Their mother is working toward a degree while substitute teaching in the Loudoun County public school system.

The Williams brothers are seeking donations to fund their two-week trip abroad. They have created a Web site to raise money for the trip: giveforward.org/williamsbrothers.