Please people, I beg you to lock up your guns. If you have children, you can’t just hide things and expect that your kids won’t get I to them. Small kids are inquisitive, and they notice things.
Certainly there are a lot of people who own firearms for home defense who don’t carry otherwise, it’s their choice, and that’s fine. The fact remains, that if you have kids, and your gun isn’t in your person, it should be locked up.
There are tons of options on the market for securing your handgun, many are quite expensive with fancy biometric locks, and all sorts of stuff, but if all you need to do is keep your kids out of trouble, something as simple as a $30 lock box could prevent something like this from happening.
Before someone comments and says that you train your kids to be responsible around guns, let me reiterate the fact that this was a 4 year old. If you are leaving firearms around where a 4 year old can get to them, you are an idiot.