More Americans were killed in 2015 by toddlers with guns (21) than were killed by terrorists (19 - which was higher than the 10-year average of 6).  Most of the deaths were the toddlers themselves, as in this tragic case.
Perhaps the outrage and hysteria in this country should be refocused a bit to the larger problem.  
Incidentally, on an average year lightening kills more than either of those causes.