The family of the late former chairman of the Nigerian Exchange Group, Abimbola Ogunbanjo, who was killed in a Southern California helicopter crash in February, has filed a lawsuit against the US helicopter company for ignoring bad weather to conduct the flight.

The former Chief Executive Officer of Access Holdings, Dr Herbert Wigwe, his wife and son were also onboard the ill-fated helicopter.

The Ogunbanjo family stated that the flight should have been grounded because of treacherous weather.

Relatives of Ogunbanjo in the court filing on Wednesday claimed that the charter company, Orbic Air, improperly flew the helicopter, despite a "wintry mix" of snowy and rainy conditions in the Mojave Desert where the crash occurred on Februay 9, the Press Enterprise reports.

One of the attorneys who filed the lawsuit, Andrew C. Robb, noted Ogunbanjo's family was seeking "answers and accountability."

"Helicopters do not do very well in snow and ice. This flight was entirely preventable, and we don't know why they took off," Robb told The Associated Press.

Ogunbanjo's wife and two children have filed a lawsuit in San Bernardino County Superior Court against Orbic Air and its CEO, Brady Bowers, alleging wrongful death and negligence.

The suit also includes the unidentified successors of Pettingill and Hansen, whom Ogunbanjo's family holds responsible. Orbic Air did not provide any comment on the matter.

The National Transportation Safety Board is currently investigating the crash.

A preliminary investigation report released by the agency in February revealed details about the helicopter's flight path and wreckage.

Witnesses reported observing a "fireball" during rainy and snowy conditions at the time of the crash.

The lawsuit seeks a jury trial for Ogunbanjo's burial expenses, funeral expenses, and other damages.

Robb & Robb, the law firm representing Ogunbanjo's family, previously represented Vanessa Bryant in her lawsuit, following Kobe Bryant's fatal helicopter crash in 2020.