Image copyright National Transportation Safety Board Image caption Investigators were only able to reach the wreckage on Monday because of weather conditions

Federal investigators have reached the site of a South Dakota plane crash that killed nine members of a prominent US business family on Saturday.

Spanning four generations, they had been travelling back home to Idaho after an annual pheasant-hunting trip.

Their plane crashed shortly after take-off at about 12:30 (18:30 GMT) local time from Chamberlain - which was under a winter storm warning at the time.

Officials confirmed that three other family members survived the crash.

Among the victims were Jim Hansen Sr and his two sons Kirk and Jim Jr - who served as executives at Conrad & Bischoff, a petroleum company, and at skincare brand Kyani, which they founded.

Two of Kirk Hansen's sons also died in the accident, along with two of his sons-in-law. The other victims were Jim Jr's son and a grandson.

They were travelling in a Pilatus PC-12 single-engine plane, which is not required to have a voice or flight data recorder, the National Transportation Safety Board (NTSB) said in a statement.

Investigators have not yet established a cause for the crash, but a spokesman told the Associated Press (AP) that weather would be one of the potential factors reviewed.

The Hansens have been described by locals in Idaho Falls as "pillars in the community".

The East Idaho News website has shared tributes from people who knew the family, including the director of a local funeral home.

Brian Wood revealed text messages that showed the two Hansen brothers had "many, many times" secretly paid for families who were struggling to afford burial expenses.

Both men and their father had also held prominent positions in the Church of Jesus Christ of Latter-day Saints, the website reported.

The pilot of the plane has not officially been named but Kirk Hansen had a private pilot certificate, AP reports.