By Dennis Romero and Minyvonne Burke

The CEO of one of Nigeria's largest banks was among the six people killed when the helicopter they were on crashed Friday night in California, a World Trade Organization official said.

The chartered helicopter departed Palm Springs at 8:45 p.m. en route to Boulder City, Nevada, but "impacted the ground" near Halloran Springs, California, at 10:08 p.m., National Transportation Safety Board member Michael Graham said at a news conference Saturday night.