Authorities have arrested the parents of a dead 4-year-old boy who authorities say may have been exposed to fentanyl while the family was staying in a Brooklyn shelter.

The parents, ages 26 and 32, initially were questioned for hours after the child suffered an apparent medical episode at the Glenwood Road Shelter in East Flatbush, according to police and law enforcement sources.

Officials say paramedics administered Narcan and observed bruising to the right side of the child's abdomen. The paramedics also allegedly said the parents told them "yes" when asked if there were drugs or fentanyl in the house.

They were charged Thursday with child abandonment and criminal possession of a controlled substance.

Toxicology results on the dead child are pending.

The "Women in Need" shelter is operated by Win, the city's largest provider of shelter for families with children experiencing homelessness.

"Win is devastated by the tragic death of this innocent child who came to reside with us in one of our shelters," a statement said. "We are working closely with the NYPD to support their ongoing investigation. We remain committed as ever to fostering a safe and supportive environment for all families that call a Win shelter home."