The helicopter was taking part in a range training operation when it crashed.
The incident occurred at the Pacific Missile Range Facility, a Navy base in Kauai, Hawaii, shortly after 10 a.m. local time Tuesday.
The helicopter was taking part in a range training operation on the base in Kekaha when it crashed on the northern area of the installation, a Pacific Missile Range Facility spokesperson said in a statement.
Emergency personnel responded to the crash, the spokesperson said. There were four fatalities.
An investigation is underway to determine the cause of the accident, the spokesperson said.
The National Transportation Safety Board also confirmed it is investigating the crash of a Sikorsky S-61N helicopter near Kekaha.
MP/PR
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