I don't often talk of religion here. But this topic, "Why does God let bad things happen?", often comes up as a reason why some choose not to believe. More, the words, "part of God's plan.." are often misused as comfort.
I am offering this video by Catholic priest Fr. Mike Schmitz. Granted it is not for everyone, but may be what is needed by someone.
I shared this video a few years ago, but I am sharing again. Just because.