Toddlers as victims of self-inflicted wounds often raise questions with me. Although I understand the superpowers of the errant two-year old, I have few arms which would be readily lifted (when loaded) or operated by one so young.
I agree, that despite the incredible climbing abilities of the little nippers, the attempt should be made to place a loaded weapon out of their reach. Like anything else, once they have it, they will mess with it until they get it to work.
For that environment, I would recommend a pistol with a magazine safety. You can leave one up the pipe, pull the mag, and it can't be fired. Put the mag at a separate high location where an adult can readily reach it, insert it, and you are ready to go if you need it, but it would be darned hard for the kid to get it operable.
Anyone with toddlers should put noisy stuff on the way to things they don't want touched, both as a distraction and as an alarm that someone is messing where they shouldn't be.
Always wondered about those myself.
I don't know many toddlers that could either pull a double-action trigger or cock the hammer on a revolver or pistol to get it to single-action. Aside from strength, their hands just aren't big enough. Or rack the slide on a semi-auto.
Either these guns were left unattended in the most ready condition possible, which would be extremely negligent, or something else was going on.