A preliminary NTSB report found that a helicopter crash near Superior that killed four family members on Jan. 2 occurred after the aircraft struck a "slackline" used by high-wire athletes.

A private helicopter crashed into a slackline in a mountainous region of southeast Arizona earlier this month, killing the pilot and all three passengers. The incident is among the first documented ...

Slackliners took the line down because of forecasted rain and high winds, but strung it up again the day of the accident. Slackliners whose valley-stretching cable led to a deadly helicopter crash in ...