 Every year, Sudden Unexpected Infant Death claims the lives of 3,600 babies, and it can happen in an instant. He was just like face down. I feel like so helpless in that moment. Soft mattresses, pillows, blankets, and stuffed animals can cause Sudden Unexpected Infant Death. The safest place for your baby is in a crib with nothing but a firm, flat mattress. For more about how to create a safe sleep environment for your baby,