Livingston County Health Department issued the following announcement on Mar 27.
Babies are safer sleeping on their backs. When a baby is on his or her back, the air tube is on top of the food tube. When a baby spits up, liquid flows back into the stomach, not the lungs. When baby is on his or her stomach, fluid can pool at the opening of the air tube and may cause choking.
This video shows the baby’s anatomy when on his or her stomach versus the back: https://www.youtube.com/watch?v=uK84x2FE3fg
Original source can be found here.