LOS ANGELES - Edwin S. Shneidman, a prominent thinker on death who helped break American taboos on discussing suicide, died May 15. He was 91.

Shneidman, who had suffered from cancer , congestive heart failure and diabetes in recent years, died at his home in Los Angeles, his son, Robert, told the Los Angeles Times.

Edwin Shneidman helped found the Los Angeles Suicide Prevention Center in 1958 in an abandoned tuberculosis hospital.

Opening such a center was a radical idea at the time but Shneidman, who had a doctorate in clinical psychology and wrote 20 books on death, said suicide was the "one truly serious philosophical problem."

Shneidman left the center in 1966 to head a national suicide prevention project that in three years increased the number of such centers in the country from 15 to more than 100.

He went on to found the American Association of Suicidology and the quarterly journal Suicide and Life-Threatening Behavior.

His study began in 1949 when he was working at a Los Angeles veterans' hospital and had to write letters of condolence to the widows of two veterans who had killed themselves. He decided to research the cases, which led to a daylong trip to the morgue and a lifelong fascination with death.