Three women in the Mendocino County Jail have been treated after overdosing on Fentanyl. On Monday evening, jail staff responded to two women having seizure like symptoms with a third showing signs of an overdose. They, along with a fourth woman who reportedly took the same substance but did not overdose, were taken to Adventist Health Hospital for treatment and were all later returned to the jail. The substance was tested and determined to Fentanyl, a strong opioid. Deputies are now conducting an investigation on how the drug got into the jail and how to prevent future incidents from occurring.