The statement was that the child put a speaker next to (the shelf) to crawl up and get (the gun)
Crawford County Prosecutor Matt Crall
Grandmother charged after her 4-year-old Galion grandson shoots himself dead with her unsecured pistol.
The woman had left a loaded.22 caliber, semi-automatic pistol on top of a shelf.
Leaving loaded and unsecured guns lying around, even on a top shelf, is irresponsible. I’ve known a number of people who think that’s an acceptable practice but it’s actually idiotic. When children live in the household, as the boy did in this case, it’s even worse, if that’s possible.
I’ve been encouraged to write a Second Edition of Serious Mistakes Gunowners Make. Sadly, I’ve acquired a lot of new material, although all of it follows the same pattern.
OTOH, this murderer should simply be thrown into an active volcano forthwith.
According to police, the shooter fired bullets at a residence from a nearby alleyway, and one of those bullets struck Trinity, who was jumping [on a trampoline] with friends.
Minn. Girl, 9, Is Fatally Shot While Jumping on Trampoline with Her Friends
https://people.com/crime/minnestota-girl-fatally-shot-jumping-trampoline/
tacticalprofessor 
The second child killed in a driveby here; the other was OTW to McDonalds. Another is in the ICU w a head wound. City fathers bemoan the violence, but that other group has zip to say about it. Oh, and no one has confessed to it or snitched about it. Probably already back in Killinois or someplace.
We haven’t seen the worst of it by a long shot, either.
I understand and agree that all of the steps and barriers BEFORE a child gets their hand on a gun are the most important. Moving one step beyond that, do you have an opinion on the presence of a manual safety being a last line of defense if all others fail? Obviously it wouldn’t help much with children of a certain age, but I’d imagine it might with a 4 year old.
I think a security box or container is the answer.