Police officers on patrol in Norway happened upon a group of young people acting confused early Sunday—and ended up discovering a mass carbon monoxide poisoning. As the BBC reports, several more similarly disoriented people emerged from an underground bunker asking for medical assistance, and police ultimately discovered a rave with about 200 guests had been held in the bunker. Portable generators used to play music at the party are believed to be responsible, per the Local.
Twenty-five people were hospitalized with carbon monoxide poisoning, including two police officers who attended to the guests; seven of the affected people were reportedly unconscious, but all are improving and are expected to recover. The oxygen level in the bunker, which was built for air raids and is nearly 230 feet deep, was reportedly down to 16%. The partygoers allegedly entered the bunker illegally, Deutsche Welle reports. (Read more carbon monoxide stories.)