William Tully Brown, one of the last remaining Navajo code talkers, died Monday at 96.

Brown was one of the roughly 400 Navajos who served the U.S. Marines and Navy by using their native language to develop a code for top-secret messages during World War II.

Navajo Code Talker William Tully Brown passed away yesterday at 96 years old.



Brown, one of the last surviving Code Talkers from WWII, enlisted in 1944 and became part of a legendary group of Native Americans who encoded messages in the Navajo language.



Semper Fidelis, Marine. pic.twitter.com/yKuYHa4DsB — U.S. Marines (@USMC) June 4, 2019

"From 1942 until 1945, Navajo code was used by the US Marines and Navy, and they tell us that we saved hundreds of thousands of lives and helped win the war in the Pacific to preserve our freedom and liberty," said Peter McDonald, president of the Navajo Code Talkers Association, according to CNN .

Brown was born in Black Mountain, Arizona, on Oct. 30, 1922. He enlisted in the Marine Corps in 1944 and served until he was honorably discharged in 1946. No cause of death was immediately available.

“The Navajo Nation has lost another great Diné warrior,” Navajo Nation President Jonathan Nez said in a statement.

U.S. Navy veteran, astronaut, and Arizona Senate candidate Mark Kelly shared his condolences on Twitter Wednesday afternoon.

Arizona and our country will always remember the brave service of William Tully Brown, who served as a Code Talker and Marine at Guadalcanal and Iwo Jima. We're forever grateful for his service and that of his fellow Code Talkers who saved countless lives and changed history. https://t.co/DXlvsT43SI — Mark Kelly (@ShuttleCDRKelly) June 5, 2019

Mark Charles, a tribal citizen of the Navajo nation who announced his 2020 presidential candidacy less than a week ago, expressed similar sentiments in a tweet of his own Wednesday morning, highlighting the fact that Tully served despite the Navajo lacking the right to vote in every state.

I am grateful for the life & service of William Tully Brown. He enlisted in the Marine Corps in 1944 & served in WWII as a Navajo Code Talker despite the fact that Native Americans were not even allowed to vote in AZ and NM until 1948. Ahéhee' shinalí.https://t.co/k869Ffsxjy — Mark Charles (@wirelesshogan) June 5, 2019

Brown was a member of the Navajo Code Talkers Association and had worked on launching a museum about the code talkers.

He is the third Navajo Code talker to pass away in the span of a month. This leaves only five members of the lauded group.