Police were called to a residence in the 800 block of North 5th St. just after 5 p.m.
"The call was for an infant that was found in a tub. I believe, as you can see, earlier it was kind of chaotic, everybody was upset. First thing we did was try to get care to that infant," Detective Dan Sweiger with the St. Joseph Police Department said.
A neighbor says a man and woman live in the house with two young children, one a baby.
"I heard some kind of screaming so I came outside to see what was going on. I saw him carrying the baby out to the cop and the cop took the baby to the ambulance," Heather Bowers, who lives next door to the residence said.
An investigation into the death is ongoing. Police say these investigations are always difficult, whether they be criminal or accidental.