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?

Investigators say a helicopter hit a highline stretched across Telegraph Canyon near Superior, killing four. Here’s what to know.

Preliminary evidence indicated a slackline of more than 1 kilometer in length was strung recreationally across a canyon.

A sightseeing helicopter carrying four family members crashed in the mountains of central Arizona after apparently striking a slackline stretched high across a canyon, killing everyone on board. The ...