U.S. safety regulators said today that a small plane that crashed on Kauai earlier this month and killed two men on board had been flying close to a mountain in poor weather.

The National Transportation Safety Board said witnesses told police that just before the accident on Kauai, they saw an airplane flying low and close to a mountain in poor weather conditions. They then heard “a loud crashing noise,” the agency said.

A search-and-rescue helicopter later found airplane wreckage in steep mountainous terrain and confirmed that there were no survivors.

Civil Air Patrol owned and operated the Cessna 172N airplane. It was conducting a routine hurricane and tsunami practice flight when the March 20 crash occurred about 13 miles north of Kekaha.

Kauai police identified the two on board as James Degnan, 76, of Princeville, and David Parker, 78, of Kapaa.