Jack Lucas, who forged his mother's signature on an enlistment document so he could join the military at 14 during World War II and who became the youngest Marine to receive the Medal of Honor, has died. He was 80.

Lucas, who was diagnosed with leukemia in April, died today at Forrest General Hospital in Hattiesburg, Miss., after asking to be removed from a dialysis machine, said Mary Draughn, a close friend.

Three years after joining the Marines, Lucas was stationed at a supply depot in Hawaii when he stowed away on a ship headed to Iwo Jima because he was afraid he would never see combat, he later recalled.

On Feb. 20, 1945 — six days after he turned 17 — Lucas was fighting Japanese soldiers in a trench during the Battle of Iwo Jima when he dove on top of two grenades and pushed them deep into the beach's volcanic ash to shield three other Marines from harm.

"I didn't think. I just immediately reacted and did what I had to do," Lucas told USA Today last year.

After one of the grenades exploded, he suffered near-fatal injuries and underwent more than 20 operations over the following months. More than 200 bits of metal remained embedded in his body.

For his actions, Lucas was presented the Medal of Honor — the nation's highest and most exclusive military decoration — by President Truman in October 1945 in a ceremony on the White House lawn.

Truman "told me he'd rather have that Medal of Honor than be president of the United States," Lucas said in 2006 in the Herald-Sun of Durham, N.C. "I said, `Sir, I'll swap you.' And all he did was laugh."

Only one other 20th century Medal of Honor recipient was younger than Lucas. He was James Aloysius Walsh, a 16-year-old Navy seaman who was honored for his heroism during the 1914 U.S. occupation of Vera Cruz, Mexico.

There are 29 surviving World War II Medal of Honor recipients and 104 overall. Since the distinction was established in 1862, there have been 3,448 Medal of Honor recipients, according to the Congressional Medal of Honor Society.

"I never really thought of myself as a hero, period, but they chose to decorate me," Lucas said in 1985 in The Washington Post. "Then I was cocky after all that fanfare. It really blew my mind, women jumping on me and kissing me. ... I got engaged four times."

People often told Lucas he should recount his war years in a book, he later recalled. At the dedication of a war memorial, he met D.K. Drum, a North Carolina writer who would co-write his 2006 book, "Indestructible: The Unforgettable Story of a Marine Hero at the Battle of Iwo Jima."

Jacklyn Harold Lucas was born Feb. 14, 1928, in Plymouth, N.C. His father died when he was 10.

When the Japanese bombed Pearl Harbor, Lucas was a 13-year-old cadet captain at Edwards Military Institute in the small town of Salemburg, N.C.

"Though I was only an eighth grader ... I would not settle for watching from the sidelines when the United States was in such desperate need of support from its citizens," he said in his book.

After he joined the Marines, military censors discovered his actual age when he wrote a letter to his girlfriend, who was 15. When they threatened to send him home, he said he would just join the Army. The Marines had assigned Lucas to the relatively safe job of driving a transport truck in Hawaii when he jumped a troop ship headed to Iwo Jima.

Following the war, Lucas married Helen, the first of his four wives, on "The Bride and Groom Show," a CBS program that featured couples and their on-air weddings. Four years later, he earned a business administration degree from High Point University in North Carolina.

In 1961, at 33, Lucas once again wanted to wear a military uniform. The Marines would have welcomed him back, Lucas later said, but he joined the Army because he wanted to jump from planes. He rose to the rank of captain but quit in 1965, bitterly disappointed that he would not be sent to Vietnam, he said in his book.

Over the next 16 years, he built a chain of successful butcher shops in the Washington, D.C., area.

"He was a character; he didn't fit any mold," said Doug Sterner, a military historian who was his friend. "Jack was very outspoken, a guy who was willing to go against the grain."

During his 1995 State of the Union speech, President Clinton introduced Lucas to the country. Sitting to next to first lady Hillary Rodham Clinton, Lucas heard the president say in part: "Fifty years ago in the sands of Iwo Jima, Jack Lucas taught and learned the lessons of citizenship. ... All these years later, yesterday, here is what he said about that day: `Didn't matter where you were from or who you were, you relied on one another. You did it for your country.' "

Lucas is survived by his wife, Ruby, whom he married in 1998, of Hattiesburg; four sons, William, Jimmy, Lewis and Kelly; a daughter, Peggy; a brother; 15 grandchildren; and 16 great-grandchildren.

Instead of flowers, the family suggests donating to the Marine Corps League, Commiskey-Wheat Detachment 1073, P.O. Box 18290, Hattiesburg, MS, 39404.