I'm also glad to hear that your baby is okay!  Those stairs can be tricky for our little guys.  I also have hardwood floors/stairs and had to get a runner, a cheapy one from Home Depot, so my babies would have better "grip."  It's a thin carpet with rubber on the back...kinda ugly...looks cheap...is cheap...but works great!  We roll it up and put it away when guests come over but keep it down for everyday use.  The only "pain" is the rug needs to straightened out every day.  
 
It's a cheap solution to a potentially costly price...one of my babies getting hurt! 
