Nigeria’s president, Bola Ahmed Tinubu, grieved the deaths in a post on X.

“Their passing is an overwhelming tragedy that is shocking beyond comprehension,” he wrote. “I pray for the peaceful repose of the departed and ask God Almighty to comfort the multitude of Nigerians who are grieving and the families of the deceased at this deeply agonising moment.”

The death of Wigwe, 57; his wife, Chizoba; and son, Chizi, shocked many in Nigeria and in the banking sector. He was widely seen as an industry leader, having been involved in two of the country’s biggest banks, including Guaranty Trust Bank, where he was previously executive director.

Under Wigwe’s leadership, Access Bank’s assets and presence grew beyond borders in several African countries.

“Dr Wigwe was a key driving force and a larger-than-life personality who brought his remarkable passion, energy and experience to the transformation of the Access franchise,” Sunday Ekwochi, group company secretary of parent company Access Holdings, said Sunday in a statement.

The bank, in a post on X, wrote that Wigwe’s “passion and unwavering commitment to excellence transformed Access into a global powerhouse”.

“His legacy of excellence and compassion will continue to inspire us all,” the statement said.

Wigwe’s death is “a terrible blow” for Nigeria and Africa’s banking industry, Nigerian presidential spokesman Bayo Onanuga wrote on X. “Wigwe had a big vision to make Access Holdings Africa’s biggest, with all the unquenchable thirst for acquisitions,” Onanuga added.

Wigwe’s interests also spanned the education sector. His private university, founded in Nigeria’s oil-rich Niger Delta region where he was from, is scheduled to open in September. Last year he said the university was “an opportunity for me to give back to society”.

The crash happened south of I-15 near Halloran Springs Road, about 120km northeast of Barstow, according to Michael Graham of the National Transportation Safety Board, which is investigating the crash.

Graham said Saturday that he did not have information about the two crew members, a pilot and a safety pilot. The aircraft did not have a cockpit voice recorder or a flight data recorder and was not required to have them, he added.

The Airbus EC-130 left Palm Springs Airport at around 8.45 on Friday and was travelling to Boulder City, Nevada, Graham said. Boulder City is about 40km southeast of Las Vegas, where the Kansas City Chiefs and the San Francisco 49ers played in Super Bowl 58 on Sunday.

Flight-tracking data shows the helicopter was travelling along the interstate about 1,000 to 1,500 feet above ground level, Graham said during a Sunday news conference. The aircraft made a slight right turn, turning south of the roadway, and the data then shows a gradual descent and increasing ground speed.

The wreckage site shows that helicopter hit the ground with its nose low at a right-bank angle, Graham said, adding that meteorologists have confirmed the weather included precipitation. The debris field was about 91 metres long.

The flight was a charter operated by Orbic Air LLC. Several people travelling on I-15 witnessed the crash and called 911, Graham said.

Witnesses reported that it was raining with a “wintry mix” at the time of the crash, according to Graham. People also reported a fire on the helicopter plus some downed power lines.

“This is the beginning of a long process. We will not jump to any conclusions,” Graham said Saturday.

Investigators on Sunday began mapping the area with drones and documenting the wreckage. They are also gathering pilot and maintenance records. A preliminary report is expected to be released within 30 days, though a full investigation will take up to two years to complete.

The crash came just three days after a US Marine Corps helicopter went down in the mountains outside San Diego during historic downpours, killing five Marines.