The people who strung the line - which is used in a sport akin to tightrope walking - had filed an aviation safety notice, raising questions about the air alert system.

How was a thin strip of nylon or polyester webbing stretched between two points to blame in the January crash that killed four near Superior?

Slackliners took the line down because of forecasted rain and high winds, but strung it up again the day of the accident.

Shortly after the crash, another helicopter flew near the slackline, the National Transportation Safety Board investigation ...

The NTSB released on Wednesday its preliminary report into the helicopter’s collision with a slackline, including new ...

This article originally published at Helicopter crashes into kilometer-long slackline in Arizona, killing four.

A preliminary report reveals the helicopter hit a slackline, a type of webbing, that was stretched across Telegraph Canyon.

The helicopter crashed after it struck a recreational slackline suspended in Telegraph Canyon on Jan. 2, killing all four ...

The National Transportation Safety Board has issued a preliminary report about the Jan. 2 helicopter crash that killed a ...

FAIRFIELD, Ohio -- In the early '80s, a couple of bored rock climbers in Yosemite National Park came up with a new way to use their gear. They strung nylon lines between two trees and tried to walk on ...