Your statement is factually incorrect according to official statistics,[1] which I found through a very easy Google search after reading your comment. (Note that the statistic shown is for all accidental falls, not just falls on stairways, and even in the aggregate all falls cause fewer deaths than car crashes.)
You said "fall down the stairs", which I addressed hours ago. Also, you aren't accounting for the hundreds of thousands of people injured and the millions of dollars of damage.