Tomas Young, an Army veteran who was paralyzed after being shot in the spine in Iraq and who later publicly denounced the war and the Bush administration officials who sent him to fight it, died Nov. 10 in Seattle. He was 34.

His wife, Claudia Cuellar Young, confirmed his death. An investigator with the King County medical examiner’s office said the determination of the cause is pending further tests.

Mr. Young belonged to the group known as Iraq Veterans Against the War and was featured on CBS News’s “60 Minutes,” ABC News and Bill Moyers’s public-affairs program. His story also was chronicled in “Body of War” (2007), a documentarydirected by talk-show host Phil Donahue and filmmaker Ellen Spiro.

In an interview with The Washington Post, Donahue described Mr. Young as an “anti-war warrior who had the credibility of serving.”

Mr. Young was a Kmart employee in Missouri when terrorists attacked the World Trade Center and the Pentagon on Sept. 11, 2001. Days later, Mr. Young enlisted in the Army. “I wanted to go to Afghanistan,” he said on “60 Minutes,” “to seek some form of retribution on the people that did this to us.”

Iraq war veteran Tomas Young in 2007. (Mark Blinch/Reuters)

Less than three years later, Mr. Young shipped out to Iraq. On April 4, 2004, the fifth day of his deployment, he was riding in what has been described as an unarmored, uncovered Humvee when his convoy came under attack in the Baghdad neighborhood of Sadr City.

A bullet struck Mr. Young near his left collarbone, severing his spinal cord. He recalled dropping his weapon and trying, without success, to move.

“I spent the next few seconds trying to yell for anybody that was within earshot to take me out,” he said, “to make it so I wasn’t going to be paralyzed for the rest of my life. But unfortunately — or fortunately, depending on how you look at it — all that I could get out of my mouth was a very tiny, hoarse whisper. And so, nobody heard me.”

Mr. Young’s wounds had left him paralyzed from the waist down. Several years later, complications from a pulmonary embolism would further erode his mobility and impair his speech.

Donahue met Mr. Young in a hospital bed at Walter Reed Army Medical Center during a visit to the military hospital with Ralph Nader, the consumer-rights advocate and independent presidential candidate who had opposed the Iraq invasion.

In their film, Donahue and Spiro juxtaposed Mr. Young’s daily physical anguish with the congressional roll-call votes authorizing the Iraq war. Some movie critics described the film as politically strident and as a “jeremiad.” Many praised its unflinching portrayal of the war’s burden as it was carried by one soldier.

In the film, Mr. Young navigates life in a wheelchair. Unable to regulate his body temperature, he dons ice packs to prevent overheating when he goes outside. Preparing to marry, he and his fiancee worry that he might suffer a bowel accident on his wedding day. In one scene, Mrs. Young’s mother struggles to attend to his catheter.

In recent years, Mr. Young’s physical condition deteriorated severely. In early 2013, he announced that he would discontinue his feeding tube and medication. He wrote an open letter to former president George W. Bush and vice president Dick Cheney.

“My day of reckoning is upon me,” he said in the letter, posted on the Web site Truthdig. “Yours will come. I hope you will be put on trial. But mostly I hope, for your sakes, that you find the moral courage to face what you have done to me and to many, many others who deserved to live.”

Several months later, Mr. Young decided that he was not ready to die. “I want to spend as much time as possible with my wife,” he told the Kansas City Star, “and no decent son wants his obituary to read that he was survived by his mother.”

Tomas Vincent Young was born Nov. 30, 1979, in Boise, Idaho, and grew up in Kansas City, Mo. He had joined the Army before his 2001 enlistment but was discharged because of a shoulder problem. His brother also served in Iraq.

“I spend a lot of time saying how proud I am of Nathan for going to Iraq and fighting his war and telling Tomas how proud I am of his staying home and fighting his war,” their mother told an interviewer.

His first marriage, to Brie Townsend, ended in divorce. Survivors include his second wife, whom he met in 2008 and married in 2012, of Seattle; his mother, Cathy Smith of Kansas City; his father, Thomas Young of Frederick, Md.; his brother, Nathan Young of Oklahoma City; a half-sister, Lisa Harper, and a half brother, Tim Weaver, both of Kansas City; his grandmothers, Inge Young of Boise and Geneva Wallen of Kansas City; and a great-grandmother, Dorotha Hart of Osceola, Mo.

“I’m hanging in there,” Mr. Young told National Public Radio last year. “And if you’re in life and you start to think things are a little too rough to handle, just think of me and what I go through, and you realize that, hey, I don’t have it so bad.”