The odds of (A) you being in a Tornado, and (B) you being in a Tornado Shelter, and (C) The house landing on your shelter and (D) nobody coming to dig you out - is close enough to 0 to not matter.
== SNIP ==
Fewer than one percent of newly-constructed homes in Moore and surrounding towns extend underground, largely due to the high water table and the red clay that most of the area's homes stand on, which absorbs moisture easily.
In the heat, the clay tends to dry out, causing a cycle of contraction and expansion that adds pressure to concrete-reinforced basement walls, causing leaks. But NPR noted that even after improvements in building technology mostly solved this problem, people avoid basements largely because of a "psychological hangover for people that are used to seeing houses from the '40s and '50s, when the technology wasn't quite as good for waterproofing."
== SNIP ==