A retired aerospace engineer for Boeing might be the most popular grandpa around his neighborhood after he built a roller coaster for his grandkids in his backyard.
Paul Gregg, who lives outside Seattle, built the coasters in his yard so his grandkids had something to do when they came to his home.
He built the coasters with safety in mind, telling Inside Edition: "Having me or their fathers push the up the lift hill guarantees there is adult supervision. The kids can't use it by themselves."