(MORE: Father who built dream tree house has to fight for new city ordinance to save it) The Minister's Tree House in Crossville, Tenn. burned to the ground, Oct. 22, 2019.

Kalli, 6, spent the last two years in treatment for leukemia. The Make-A-Wish Foundation and the governor helped her get her dream tree house.

A crew took only three days to build the tree house for Dixon, and it's anything but ordinary. Jeff Summers, Make a Wish Oklahoma CEO, smiled when talking about Dixon's request.

It was a level of difficulty that would keep Barnhart grappling with his tree through five years of labor, some $12,000 to $15,000 in materials and many harrowing moments on ladders.