"Oh, my God!"

Another thing I'll say with conviction is that if you see a toddler falling from a chair, it is never best to scream "Oh, my God!".

This just frightens the child and maybe convinces him/her into thinking the situation is worse than they think and causes them to cry louder/longer.

You might think that screaming such a thing could alert others to the danger and possibly danger could be averted but I say something else should be shouted. Something like "catch the baby" same amount of syllables and folks know what's going on.

But maybe that's just me.