Sudden Infant Death Syndrome. This is used of computer equipment, mainly. It may offend people who don't Know.

SIDS has also been called crib death. The term is applied to deaths of infants due to no other apparent cause (e.g. carbon monoxide poisoning, heart failure, ...). Most such deaths occur when babies are sleeping. There is great discussion as to whether the endedness of babies (whether they sleep on their tummies or their backs) has any influence on SIDS risk.