Four people were killed after a privately owned helicopter crashed in a remote mountainous area east of the Valley late Friday morning, according to the Pinal County Sheriff’s Office (PCSO).

Authorities identified the pilot as 59-year-old David McCarty of Queen Creek.

The three passengers were his family members: Rachel McCarty, 22; Faith McCarty, 21; and Katelyn Heideman, 21.

All four were pronounced deceased at the scene.

PCSO officials confirmed the helicopter departed from Pegasus Airpark in Queen Creek prior to the crash.

Preliminary information indicates the aircraft went down around 11 a.m. in the mountains near Telegraph Canyon, south of Superior.

According to investigators, the helicopter struck a recreational slackline that was more than half a mile long and strung across the mountain range.

An eyewitness contacted 911 after observing the aircraft hit the line before descending into the canyon below. Initial reports suggest the impact caused a rotor blade to separate, leading the helicopter to overturn before crashing into the mountainside.

The Federal Aviation Administration (FAA) confirmed the aircraft was an MD 369FF helicopter and stated that four people were on board at the time of the crash.

Deputies and search-and-rescue teams responded immediately; however, access to the site was significantly delayed due to steep, rugged terrain. Rescue crews reached the remote crash location at approximately 5 p.m., and officials confirmed the fatalities several hours later.

As a precaution, the FAA issued a temporary flight restriction (TFR) over the area to ensure airspace safety during recovery and investigative operations.

The FAA and the National Transportation Safety Board (NTSB) are jointly investigating the incident.

The NTSB will lead the investigation and is expected to release additional information as the inquiry progresses.

Authorities have expressed condolences to the victims’ family as recovery efforts and the investigation continue.