Is it possible for a person to suffocate without visible signs on the body, e.g if you drank

Alcohol and fell asleep face down into pillows.:confused:

If you are locked in a sealed room (the classic "locked in a bank vault"), there would not be any marks on the body.

There should always be some signs, ie impressions of the pillow on the face, signs of which way they were laying when they died, if the body was moved and so on. Also perhaps fibers in the mouth or throat or even lungs.

Is it possible for a person to suffocate without visible signs on the body, e.g if you drank

Alcohol and fell asleep face down into pillows.:confused:
I've been told that Petechiae should be present if suffocation took place even if it was accidental death is this true.