>>> FINALLY TONIGHT HERE, THE TEACHER, HER DOG, AND THE STUDENTS WHO WERE DETERMINED TO DO SOMETHING. BUT WHAT THEY'VE DONE IS AMERICA STRONG. TONIGHT, IN CHARLOTTE, NORTH CAROLINA, THE HIGH SCHOOL STUDENTS AT PROVIDENCE DAY SCHOOL ON A MISSION TO HELP THEIR TEACHER AND HER BELOVED DOG. EVERYONE AT SCHOOL KNOWS BENTLEY, THEIR MATH TEACHER MS. ASHLEY LIBERTO'S GOLDEN RETRIEVER. EARLIER THIS YEAR, BENTLEY WAS DIAGNOSED WITH CANCER, AND HAD TO HAVE HIS FRONT RIGHT LEG AMPUTATED. IT DIDN'T STOP BENTLEY, SLOWLY RECOVERING, RELEARNING TO WALK, SWIM, AND PLAY FETCH. >> STILL HAS IT. >> BUT THE STUDENTS HAD AN IDEA. >> DAVID, WE'D LIKE YOU TO MEET BENTLEY. >> MR. TODD JOHNSON'S COMPUTER SCIENCE CLASS GETTING TO WORK. >> HI, DAVID. >> MR. JOHNSON. >> SHE NEEDED HELP IN FINDING A WAY TO GET BENTLEY A LITTLE MORE MOBILE. I KNEW MY STUDENTS WERE UP TO THE CHALLENGE. >> THE STUDENTS BEGAN BUILDING A PROSTHETIC LEG. THEIR DESIGNS COMING TO LIFE ON THE 3D PRINTER. HOLDING THE PROTOTYPES. BENTLEY ARRIVING AT SCHOOL, GETTING FITTED FOR HIS NEW LEG. >> THIS IS A GOOD ONE. >> THE STUDENTS MEASURING, ADJUSTING THEIR DESIGNS. SENIOR BRANDON HOLLIS. >> KNOWING THIS PROJECT WOULD HAVE THIS REAL WORLD TANGIBLE IMPACT ON A LIFE, IS WHAT REALL. >> JUNIOR HOUSTON DEE. >> SOMETIMES YOU JUST GOT TO GO FOR IT. YOU GOT TO FIND SOMETHING THAT YOU'RE PASSIONATE ABOUT AND TAKE YOUR OPPORTUNITY. >> AND THIS EVENING, JUST LOOK AT BENTLEY. HIS FIRST STEPS IN THEIR NEWEST DESIGN. AND RIGHT HERE TONIGHT -- >> HEY, DAVID. >> THEIR TEACHER, MS. LIBERTO, AND HER BENTLEY. >> MY REACTION WHEN THE STUDENTS CAME UP WITH THE DESIGN WAS JUST -- I WAS SO MOVED, SO TOUCHED BY THEM. >> TONIGHT, THE STUDENTS COMING TOGETHER FOR THEIR TEACHER AND HER DOG. >> HI, DAVID. >> BYE, DAVID! >> BENTLEY COMING RIGHT TO THE CAMERA THERE. GO BENTLEY, AND THOSE