Hikers reported seeing the helicopter crash into the waters about a quarter of a mile (0.4 kilometers) off the Na Pali Coast and called police around 1:20 p.m., the police department said in a statement.
The Robinson R44 helicopter was part of Ali‘i Kaua‘i Air Tours and Charters, authorities said.
One person's body was recovered around 2:30 p.m. Thursday as crews continued to search for the remaining two people. Their identities were not immediately released by police.
The National Transportation Safety Board will investigate.
RHM/PR