A private helicopter crashed in a mountain range outside Phoenix on Friday, killing all four people aboard, authorities said.
The crash occurred around 11 a.m. local time Friday and involved an MD 369FF helicopter, according to the Federal Aviation Administration.
The Pinal County Sheriff’s Office said an eyewitness who called 911 said the helicopter struck part of a recreational slackline that had been strung up across the mountain range before falling to the bottom of the canyon.
Slacklining is an activity, similar to tightrope walking, that involves balancing on a flat piece of webbing between two anchor points, according to Slackline U.S…