This dad built a two-story roller coaster in his backyard

Will Pemble built his first roller coaster when his 11-year-old son asked if it would be cool to have one in the backyard. Will hopped on the idea and used his background in aeronautical and computer engineering to make it happen. The latest one he built in his backyard is two stories tall and goes up to 23 mph. It's his fifth roller coaster and is named the Goal Boss.