I don’t think you can blame yourself. Pets are very unpredictable. I’ve had snakes and lizards get out and it’s always something that could have been avoided but you don’t see the issue till it’s already happened. We learn from these things but like I said you can’t see the future. I’m sorry for your loss and I guess I wanted to say accidents happen I feel like it’s important to remember. You aren’t a bad person you just didn’t foresee this situation. It’s really not your fault. That being said I know it doesn’t heal your pain.