Katrina and Mike Carr met while working at a summer camp for special-needs children. After they married six years later, the couple followed their passion of making a difference in the lives of others by adopting four kids from Kazakhstan who'd been abandoned at birth. Two of the children were born with Amniotic Band Syndrome, which caused Ryanne, now 7, to have both legs and one arm amputated, and Rina, 3, to lose a leg. Their brother Nikolas, 9, was recently diagnosed with Sensory Integration Dysfunction, which causes an inability to organize information as it comes through the senses. Compounding the family's struggles, health problems have required their father, Mike, 41, to have both pancreas and kidney transplants over the past decade. Yet, for all the challenges Ryanne, Rina, Nikolas and Mike face -- and which Katrina, 37, and daughter Haydn, 8, face with them - the Carrs carry on with unfailing spirit and optimism. Being a triple amputee hasn't stopped Ryanne, for example, from climbing trees, riding a handcycle and running. She's learned to rely on different prosthetics for different activities. Katrina, who has a master's degree in education, home-schools her children who otherwise would miss public school classes too often for doctors' appointments. Mike has taught environmental education at camps for special needs kids and is also an artist and jewelry designer.

"Extreme Makeover: Home Edition" travels to Pine Mountain Valley, GA, to meet Jeremy and Jennifer Williams, whose son, Jacob, was diagnosed with Spina Bifida before he was born. Then, several years after Jacob's birth, Jeremy was diagnosed with Lou Gehrig's disease. Now the home Jeremy and Jennifer bought 13 years ago is falling apart around them. In addition to mounting repairs, the home is too small to accommodate two disabled family members. NFL Star Michael Oher and the Tuohy Family ("The Blind Side") are the "Get on the Bus" volunteers, while ESPN football analysts Herm Edwards, Mark Schlereth, Mark May and Desmond Howard are special guests. Plus, Demi Lovato and Wilmer Valderrama also appear in the episode.