The first police report concluded that “a chain of unfortunate circumstances” led to the deaths after poor sound in the back prompted fans at a Pearl Jam concert to surge toward the stage, killing the nine men and injuring 43 others.

The June 30 tragedy was compounded by confusion over who should stop the music, according to the report, which was released in December.

Based on 977 interviews with band members, organizers, rescue workers and others, the initial investigation mainly put the blame on the crowd of up to 50,000 people.

Finn Tonnesen, whose 17-year-old son Allan died, has led the criticism and called for a new and broader study.

Tonnesen, who was not immediately available for comment, has said in several recent interviews that police have not thoroughly investigated the roles of the festival organizers and the rescue teams.

The first report was unclear why the organizers didn’t stop Pearl Jam’s performance when they realized what was happening. There were conflicting accounts about who had the authority to stop the concert.

On Thursday, Justice Minister Frank Jensen bowed to the criticism and asked the state prosecutor for the Roskilde area to reopen the investigation.

Festival organizer Leif Skov said he welcomed a second investigation.

“There have been doubts about the reasoning the police made in their report,” Skov told public radio. “We have long supported the parents’ wish that this doubt is removed.”

Eight people were trampled to death in Roskilde, 40 kilometers (25 miles) west of the capital, Copenhagen. An Australian man died of his injuries a few days later.

The rock festival, one of Europe’s oldest, was first held in 1971 and was inspired by the 1969 Woodstock Festival in upstate New York.