Conversation Landmine

So you're just having a great flowing conservation with a group of friends. The topics have been great while you can see some people are bored. So in order to get the others interested in the conversation, you smoothly change the conversation. You do it with all good intentions. Then, the unimaginable happens...
The conversation takes a turn for the worst. You essentially hit a conversation landmine. All the conversation taken before does not matter anymore. The deed has been done, the landmine has been hit like a bomb in minesweeper. The night is ruined no matter how much work you have done before! A common conversation landmine topic is religion. Easily one of the most common topics I have seen in my experience that end terribly. But any topic can be a landmine, be aware that people may have personal issues/strong feelings about any subject (Including home states/towns). Yelling and screaming may occur depending on the intensity of the conversation.
But it may be impossible to detect these landmines. But learn from previous experiences; it'll be hard to forget!