The final day of the Electric Zoo Festival was cancelled after two concert-goers died of an apparent overdose.

According to New York Daily News, the festival, which was slated to conclude Sunday, was cancelled after two patrons died of an overdose of MDMA, a drug commonly referred to as “Molly.” The drug, which typically mixes other chemicals found in ecstasy pills, took the lives of 23-year-old Jeffrey Russ and 20-year-old Olivia Rotondo.

Newsday notes that a handful of other concert goers were also taken to the hospital after using ecstasy, and currently remain in the ICU.

A statement from Mayor Michael Bloomburg’s office was released Sunday following the cancellation saying, “The Electric Zoo organizers have worked with City officials to reduce health risks at this event, but in view of these occurrences, the safest course is to cancel the remaining day of the event."

The festival posted on their Facebook that refund information would be available soon in addition to posting a message to the families who are mourning at this time. “The founders of Electric Zoo send our deepest condolences to the families of the two people who passed away this weekend,” the statement reads according to the Daily News. “Because there is nothing more important to us than our patrons, we have decided in consultation with the New York City Parks Department that there will be no show today."

Armin Van Buuren, Sebastiona Ingrosso, Steve Aoki and Laidback Luke were slated to headline Sunday afternoon’s festivities.