Roughly 40 hours before rangers said they were notified of two dead bodies in Isle Royale National Park, spurring them to hike overnight to a remote campground, a hiker called police and reported screaming and threats of murder and suicide at the site full of campers.

“For about the last hour, hour plus, there is someone down there who is completely unhinged,” the caller told a Michigan police dispatcher in early June, according to audio of the call obtained Monday by the Minnesota Star Tribune. “He’s still screaming. We’ve heard him say ‘go ahead and kill yourself, I’m going to kill myself, I’m going to murder us all.’”

Park service officials declined to answer questions about whether law enforcement responded to the site between the warning of potential violence at roughly 12:10 a.m. on June 7 and the time rangers arrived at the campground early June 9.

The caller said it was a “very full campground” with at least three other groups in addition to their own and the person screaming. The caller said they packed up in the dark and left South Lake Desor Campground, on the island’s interior, and headed toward the tiny enclave of Windigo 11 miles west.

“How scared we are, we’ll be there in an hour,” the person said.

The lack of information released by federal investigators has fed rumors about the deaths and drawn criticism from some who rely on Isle Royale tourism for their businesses.