LOS ANGELES — Togo Tanaka, a former journalist and businessman whose reports on life inside the Manzanar internment camp illuminated divisions in the Japanese-American community after the attack on Pearl Harbor and the tensions that eventually erupted in riots at the World War II-era detention center, has died. He was 93.

Tanaka died of natural causes May 21 at the Ronald Reagan UCLA Medical Center, according to his daughter, Christine.

As editor of the English language section of the bilingual newspaper Rafu Shimpo, Tanaka helped oversee the last issue in the spring of 1942 before 110,000 Japanese-Americans on the West Coast were rounded up under President Franklin Roosevelt’s Executive Order 9066 and forced to relocate to detention centers scattered across several states. Tanaka was sent to Manzanar, located in California’s Owens Valley at the foot of the Sierra Nevada.

Because of his journalism background, Tanaka worked as a camp historian documenting the internee experience for the War Relocation Authority. He also wrote reports for a University of California, Berkeley, study on the evacuation and resettlement of Japanese-Americans during the war.

“He left hundreds of rich daily accounts of everyday life” at Manzanar, said University of Southern California professor Lon Kurashige, an expert on Japanese-American history and identity. “These reports … are a rare and intelligent window into not just Manzanar but Japanese-American life in pre-war Los Angeles.”

His diligent reporting on every aspect of camp life, including the political factions dividing Manzanar’s population, “got him into a lot of trouble,” said Arthur Hansen, a Manzanar scholar and emeritus professor of history and Asian-American studies at California State University, Fullerton. So did his unflinching support of the United States. Tanaka advocated cooperation with the government that had branded lawful Japanese- Americans as security threats, and forced them to give up their homes and livelihoods for confinement behind barbed wire.

“What we didn’t realize at the time was that we would soon be identified as informers, spies and dogs, people who were abusing or invading the privacy of the evacuees,” Tanaka said decades later of himself and another camp historian. Stripped of his liberty by the U.S. government and hated by many of his fellow Japanese-Americans, he was “truly in a no-man’s-land,” said his son, Wesley.

Born in Portland, Ore., on Jan. 7, 1916, Tanaka grew up in Los Angeles, where his immigrant parents ran a small vegetable store. At 16, he graduated from Hollywood High School and entered the University of California, Los Angeles, where he wrote for the Daily Bruin and majored in political science, earning a bachelor’s degree in 1936.

The day after Pearl Harbor was bombed on Dec. 7, 1941, FBI agents arrested scores of Japanese immigrants considered “enemy aliens.” Tanaka was one of the few American-born Japanese rounded up in the sweep. He was held for 11 days without explanation and was not permitted to contact anyone, including his wife, Jean, who was expecting their first child.

He was released on the 12th day without having been charged with any crime. Four months later, on April 23, 1942, he and his family were evacuated to Manzanar, which would eventually be occupied by 10,000 people of Japanese descent, most of whom were American citizens from Los Angeles County.