A helicopter appears to have crashed into a slackline strung across part of a remote Arizona canyon for an extreme tightrope-style activity, killing all four passengers.
The slackline was “more than one kilometer long,” according to the Pinal County Sheriff’s Office in Arizona, which added that a witness reported “seeing the helicopter strike a portion of the line before falling to the bottom of the canyon”.
The slackliners had filed an official aviation safety notice, known as a Notam, leading to questions about whether the pilot had seen the alert.