Do not feel guilty. It is not you who was the cause of your friends passing. There is no way you could have caused it. But there is a possibility you saw it "before" it happened. Dreams have many major sources. Some rise out of our daily likes and dislikes. Some arise out of latent impressions in the mind so old you would have trouble imagining. Still others are "premonitions". Premonition means "to warn". Now take this into account. There is no future, nor is there a past. We, who live on earth, experience linear time, but in truth, in absolute realities, there is no time. There are no future lives or past lives because they are happening now and we already lived it, so what happens sometimes is when we relax and allow for no distractions, we can catch a glimpse of the "future". But most of us do not have time to sit and relax and allow ;meditate, so that information that we see is given to us at the only time we are receptive...during sleep time. That is what possibly happened. So hey, now you can get a premonition...try meditation and maybe you'll get more. Be still and know...