Several West Point cadets were among six young men on spring break who overdosed this week on what was believed to be cocaine laced with fentanyl at a rental home in Wilton Manors, Florida, officials said Friday.

When local police arrived at the home around 5 p.m. Thursday, two bystanders were performing CPR on two unconscious men on the lawn, Battalion Chief Stephen Gollan of the Fort Lauderdale Fire Rescue said in an interview. Two others were unconscious inside the house, he added.

The two bystanders had not used the substance, but they also went into respiratory arrest because of their exposure from performing mouth-to-mouth resuscitation, Gollan said.