Cause for sudden infant death syndrome. (SIDS)
1. Depressed mother's killing their children. Very common.
2. Vaccines. Hospitals are gay enough to give infants a vaccine for a sexually transmitted disease on their first week of birth. SAD! Obviously some babies have an allergic reaction and die.
You know what probably doesn't cause SIDS?
Cigarette smoke on a parents hands. There is nothing really different between Cigarette smoke and smoke from fires. Humans lived around fires for hundreds of thousands of years at this point.