Arrested is 19-year-old Jacqueline Figueroa of the 1000 block of Kirkwood Street.
Investigators say Figueroa left her 3-month-old baby boy alone for several hours last night.
On Friday morning, police say, the baby was found unresponsive by a family member.
The family member, police and medical personnel attempted CPR on the baby, but those attempts at resuscitation were unsuccessful.
The baby was pronounced dead at the hospital.
Figueroa was charged with one felony count of endangering the welfare of a child.
No bail information was immediately available.