A preliminary investigation into the February 9 helicopter crash that killed the Chief Executive Officer of one of Nigeria’s largest banks did not address what caused the fatal accident, according to a report from The Associated Press (AP).

AP reported that investigators with the National Transportation Safety Board on Friday released a preliminary investigation report which outlined the flight path across a remote stretch of desert on a rainy night and provided details about wreckage that was strewn across 100 yards (91.44 metres) of desert scrub. However, the AP reported, it did not address what might have caused the helicopter to go down.

Herbert Wigwe, chief executive of Access Bank, and his wife and 29-year-old son were among those aboard the helicopter. Also killed was Bamofin Abimbola Ogunbanjo, former chair of the Nigerian stock exchange.

Both pilots — Benjamin Pettingill, 25, and Blake Hansen, 22 — also died.

The helicopter left Palm Springs Airport and was travelling to Boulder City, Nevada, which is about 26 miles (40 kilometres) southeast of Las Vegas, where the Kansas City Chiefs and the San Francisco 49ers were set to play that Sunday in Super Bowl 58. Wigwe’s destination after the plane landed has not been confirmed.

AP News said flight tracking data analysed by investigators, showed the helicopter was heading in a southeasterly direction as it gradually descended in altitude and increased in ground speed before the crash.

Investigators found the fuselage was fragmented, and the cockpit and cabin were destroyed. Damage to the engine and the metal deposits that were found would indicate that it was operational at the time of the crash.

The report also cited law enforcement, saying several witnesses who were traveling in vehicles along Interstate 15 had called 911 to report observing a “fireball” to the south.

The agency’s investigation is ongoing.