A father in California built a roller coaster in his backyard for his son.
When 10-year-old Lyle Pemble asked his dad for a roller coaster, he couldn't think of a good reason to say no.
It took Will Pemble about six weeks and cost $3,500 to build the single-rider coaster in the family's backyard, CBS San Francisco reports.
Pemble felt it was a fun way to apply subjects his son was learning in school, like mathematics, physics and science.
Read the full story from CBS San Francisco here.