A helicopter crash in a remote Arizona canyon killed a local man and his three nieces on his wedding day after the aircraft apparently struck a slackline strung across the terrain, authorities said.

FOX 10 in Phoenix reported that the victims of the crash, which happened Friday, were identified by family members.

The crash happened near Superior in Pinal County, east of the Phoenix area, shortly after the helicopter took off from Pegasus Airpark. All four people on board were killed when the aircraft plunged to the canyon floor.

Family members said the pilot was David McCarty, a Queen Creek man originally from Oregon, who was flying his nieces – Katelyn Heideman and sisters Rachel and Faith McCarty, all in their early 20s – to see the sights before his wedding ceremony.

Eyewitnesses told family members they saw the helicopter’s blades detach moments before it plunged to the canyon floor.

Relatives said McCarty was an experienced pilot who owned multiple helicopters and had flown the canyon numerous times without incident, adding that the short flight was meant to be a joyful outing ahead of what was supposed to be a celebratory day.

"The families lost 50% of their children on the wedding day, which was supposed to be a celebration," a family member told FOX 10 Phoenix. "It’s extremely tough. Nobody ever anticipates this sort of thing to happen, and it’s just heart-wrenching."

The loss has rippled through the family’s hometown of Echo, Oregon, where relatives said the close-knit community is struggling to cope with the deaths of three young women at once.

"They’re just struck with grief," a relative told the station. "When they say it takes a village to raise a child, that’s the epitome of these communities. Everybody had a hand in raising these girls."

The Federal Aviation Administration (FAA) and National Transportation Safety Board (NTSB) are currently investigating the crash to determine the official cause.