Authorities say the parents of twin 5-year-old children found dead Monday inside a Mount Hope apartment are cooperating in the investigation.

After arriving at 240 East 175th St. Monday morning, authorities say they found the kids unresponsive while their mother was also inside of the apartment. Neighbors say they saw her walking out of the building with first responders. She was taken to the hospital for being emotionally distraught.

According to police, the family never had a history of domestic violence or any reported run ins with Child Protective Services. Both parents of the boy and girl are cooperating with police to determine exactly what happened while their father was outside of the home.

Authorities have ruled out carbon monoxide as a possible cause of death as FDNY say the air inside of their home was safe.

The medical examiner has yet to determine a cause of death.