Oh no! I'm so sorry. My heart goes out to your whole family.
We buried Bobber in the backyard under the lilac trees tonight. Nikolai got upset a little. He has been asking if Bobber will get back up, or if he bites now. It is so hard for him to understand at this age.
Oh no, not Bobber! I am so, so sorry! My heart aches for you and your family.
I don't know if it would help, but back when I helped out in daycare, we had these funky-looking plastic guards on the doors so kids couldn't open them. They just spin freely unless you grasped tight enough to turn the knob as you normally would.
The hook/eye is a good idea!
@AkasyaEllric suggested putting a hook and eye lock on the door, high up so it will stay locked closed. Nikolai unfortunately has outsmarted the door knob covers!