John Kinsel Sr., one of the last remaining Navajo Code Talkers who transmitted messages during World War II based on the tribe’s native language, has died. He was 107.

Navajo Nation officials in Window Rock announced Kinsel’s death on Saturday.

Tribal President Buu Nygren has ordered all flags on the reservation to be flown at half-staff until Oct. 27 at sunset to honor Kinsel.

“Mr. Kinsel was a Marine who bravely and selflessly fought for all of us in the most terrifying circumstances with the greatest responsibility as a Navajo Code Talker,” Nygren said in a statement Sunday.

With Kinsel’s death, only two original Navajo Code Talkers are still alive: Former Navajo Chairman Peter MacDonald and Thomas H. Begay.

Hundreds of Navajos were recruited by the Marines to serve as Code Talkers during the war, transmitting messages based on their then-unwritten native language.

They confounded Japanese military cryptologists, who were breaking the U.S. military’s codes routinely during World War II.

“It was taken for granted they could interpret whatever we were transmitting,” Richard Bonham, a World War II radio operator, told “60 Minutes” in 2002. 

The Code Talkers also participated in all assaults the Marines led in the Pacific from 1942 to 1945, including at Guadalcanal, Tarawa, Peleliu and Iwo Jima.

The Code Talkers sent thousands of messages without error on Japanese troop movements, battlefield tactics and other communications crucial to the war’s ultimate outcome.

The language lacked modern military terms, so they came up with creative solutions, like substituting radar for owl — a bird that can see far away — and hand grenade for potato — because of their similar shapes.

Kinsel was born in Cove, Arizona, and lived in the Navajo community of Lukachukai.

He enlisted in the Marines in 1942 and became an elite Code Talker, serving with the 9th Marine Regiment and the 3rd Marine Division during the Battle of Iwo Jima.

President Ronald Reagan established Navajo Code Talkers Day in 1982 and the Aug. 14 holiday honors all the tribes associated with the war effort.

The day is an Arizona state holiday and Navajo Nation holiday on the vast reservation that occupies portions of northeastern Arizona, northwestern New Mexico and southeastern Utah.