The last of the 29 Navajo "Code Talkers" — who developed an unbreakable code that helped win World War II — has died.

Chester Nez, of Albuquerque, N.M., died Wednesday morning of kidney failure. He was 93.

Judy Avila, who helped Nez write his memoirs, says Nez's death came unexpectedly.

Nez was in the 10th grade when a Marine recruiter went to the Navajo reservation looking for young men who were fluent in Navajo and English. Nez told the Associated Press in a 2010 interview that he kept the decision to enlist a secret from his family and lied about his age.

Nez became part of the 382nd Platoon tasked with developing a code that stumped the Japanese. Hundreds of Navajos followed in the footsteps of the original Code Talkers.