In the United States, a Military Helicopter crashed, 4 people killed

Helicopter crashed in the United States of Hawaii, in this incident, four people died.
According to sources, after taking off, ten minutes later, the helicopter crashed.
According to US Navy, the helicopter belonged to a private company. It was the training flight that was crashed in the US state of Hawaii.
To determine the cause of crashing the plane, an investigation is in the way.