A survey by the Journal of Urban Health finds that an estimated 4.6 million kids live in a home with at least one loaded and unlocked firearm. A couple of findings to think about: ". . . female gun owners in homes with children are more likely than male gun owners in homes with children to store at least one gun loaded and unlocked." and "Households in which any gun is owned for protection are significantly more likely to contain a loaded and unlocked gun than are homes in which no guns are owned for protection, as are households with at least one handgun, compared to those with no handguns."
This does not have to be - there are a wide variety of reasonably priced quick access handgun safes available at any major sporting goods retailer for those who feel they must have this option.