More than 22 million U.S. children live in homes with firearms.
In 43 percent of those homes, the guns are not locked up or fitted with trigger locks, according to a national survey.
The study, reported in the "American Journal of Public Health," analyzed gun storage practices in six thousand nine hundred households with children.
The study found that nine percent of homes kept firearms unlocked, and loaded. Those homes represent 1.7 million children.
Another 4 percent of the homes have guns that are unlocked and have ammunition nearby.
That means that about 2.6 million homes had firearms stored in a way most accessible to children.
Researchers found that many parents know guns should be locked up but there is a disconnect between knowledge and action.
They may think the top shelf of a closet or a sock drawer is secure. But children are notoriously curious and may find them anyway.
Experts say parents should look at their own firearm storage and also ask pointed questions about weapons at their friends' homes as well.
This is one area where it’s not possible to be too cautious.