Six West Point cadets were hospitalized after what appeared to be a mass accidental fentanyl overdose on Thursday. As of Saturday, two of them remained critical and on ventilators, two were in stable condition, one was in good condition, and one had been released.

The six had been part of a larger group that rented a house north of Fort Lauderdale, Fla. for spring break. On Thursday afternoon, four of the vacationing students took what they believed was cocaine and were overcome by the powerful effects of the substance with which it had apparently been laced. As some of them went into cardiac arrest, two of their friends attempted CPR, exposing themselves to the same narcotic and also suffering severe symptoms.

A West Point spokesman said, “The U.S. Military Academy is aware of the situation involving West Point cadets, which occurred Thursday night in Wilton Manors, FL. The incident is currently under investigation and no other details are available at this time.”

On Friday, Wilton Manors Police announced they had made an arrest related to the incident but did not give out additional information.