Either when I'm falling asleep or just waking up, in that half/asleep stage, sometimes I hear the voices of several people I know call my name with some urgency. I always get the impression that I fell asleep while I was with them somewhere, and I wake myself up to find it was all in my head. It's always left me rather worried though, because of the tone of urgency in their voices...
I've always brushed it off as unconsciously thinking about them, but a little while ago I had a rather vivid daydream where the same people were calling my name with the same tone, but it was matched up with a mental image of a horrible accident, and they were trying to bring me back to consciousness. All I remember from [the mental picture of the dream] is a circle of blurred faces, and not being able to breathe. And their voices, calling.

The whole thing has been unsettling me. Could it mean anything?
A little more on the background of these people-they are all people I have either known for quite some time or am close friends with, but unfortunately I only see them about once a month. Another strange note is that one of my closest friends that is part of the group wasn't there for some reason.
That's about all the details I could pull out of it.
Any interpretations?