Port St. Lucie police said an infant's death Wednesday morning is being investigated by detectives.
Officers responded to a house in the 3100 block of SW Nutley St. at 10:45 a.m.
When they arrived, they found the child's father performing chest compressions on the 9-month-old, who was in cardiac arrest.
Officers took over the chest compressions until personnel with St. Luce County Fire District arrived and pronounced the infant dead.
Police said detectives learned that the infant was placed in bed with an older sibling around 10 p.m. Tuesday.
Authorities said the infant was then found Wednesday morning face down in a space between a wall and bed.
Investigator said there were blankets in the space, underneath the infant, which appeared to have been placed there to fill the gap between the wall and bed.
Police said there were no obvious signs of physical trauma to the infant, and no evidence to suggest the child's death was an intentional act.
However, police said the home was unsanitary and there were eight children living at the residence with one parent. The Department of Children and Families was notified and responded to the scene.
An autopsy is being performed on the infant.
Family members are cooperating with detectives, according to investigators.
Dr. Elizabeth Murray, a pediatrician and spokeswoman for the American Academy of Pediatrics, says parents need to remember the ABCs of safe sleep.
"Make sure that our babies are alone, on their backs, in their own safe sleep space every single time when they're put down to rest. So, whether in a crib or a Pack 'n Play, or if they're really little, a bassinet," Murray said.
Murray said there is a suffocation risk if infants don't sleep alone or if there are too many items in the crib.
"Brand new babies in the first few months of life don't have the head control and the ability to get things off of their face. So, if they start having difficulty breathing or start rebreathing air, they just don't have the ability like a toddler or a bigger kid to move stuff out of the way," Murray said.