A teenage girl was being questioned by police after her newborn baby mysteriously died, law enforcement sources said.

The 15-year-old teen gave birth to a baby girl inside her home in the Bushwick Houses on Wednesday morning, sources said.

After the delivery, she swaddled the infant in a blanket and left her unattended, sources said.

The girl’s mother, who had no idea her daughter was pregnant, called 911 around 10 p.m. last night after finding the unconscious infant, sources said.

The infant was rushed to Woodhull Medical Center where she was pronounced dead.