http://www.firstcandle.org/new-expectant-parents/about-sids-suid/sudden-unexpected-infant-deaths-suid-facts/
This document also available in Spanish
SIDS is the sudden, unexpected death of an apparently healthy baby under one year of age. There is no known way to prevent all sudden infant deaths, but there are lifesaving steps parents and caregivers can take to help protect their baby from SIDS and SUID, including suffocation and accidents during sleep.