When it comes to heading to warning signs, us humans haven’t done very well. In fact we are used to ignoring warning signs till it’s too late. Maybe we are too optimistic or just too lazy and short sighted to see our own mistakes. Whatever it is, we could do well to be a little more open to such warning signs. Let these historical mistakes that led to great disasters be a lesson to us. Here are 7 warning signs that we ignored and then faced disastrous consequences.