Del Olmo was pronounced dead shortly after noon at Good Samaritan Hospital near downtown.
In announcing Del Olmo's death to the newspaper's staff, Managing Editor Dean Baquet said Del Olmo was "one of the most beloved and valued members of the Los Angeles Times family."
"I don't have to say how much of a blow this is to all of us, and how painful the past few hours have been," Baquet said. "As much as anyone at the paper, Frank has been an important part of the life of the city, as well as The Times. We'll all miss him a great deal."
Times Editor John Carroll praised Del Olmo as someone who was "known nationally as an accomplished journalist who always had time to help a colleague get a foot on the ladder."
"The number of Latino journalists who hold good jobs today because of Frank is beyond calculation," Carroll said. "Here at the paper he will be remembered with respect and affection. For the staff, this has been a shattering day."
Del Olmo shared a 1984 Pulitzer Prize for meritorious public service for the series "Southern California's Latino Community."
During his nearly 34 years at The Times, he was an intern, a staff writer specializing in Latino issues and Latin American affairs, an editorial writer, deputy editor of the editorial page, a Times-Mirror Foundation director and an assistant to the editor of The Times. The last position put him on the masthead — the first Latino to be listed among the paper's top editors.
"It was important that his name was on the masthead not just as a symbol but because of what he was doing," said Felix Gutierrez, a visiting professor of journalism at USC and longtime Del Olmo friend. "He was always representing those who couldn't get in the room."
Del Olmo was named associate editor of the newspaper in 1998, continuing his efforts to advocate for Latinos and Latino journalists.
"He fought quiet but effective battles inside the paper and out when he felt the Latino community was being wronged or ignored," said Hector Tobar, a Times correspondent in Buenos Aires who had known Del Olmo 16 years. "There are few Latino reporters who have worked at The Times over the past 20 years who are not indebted to him in one way or another."
Another colleague, Oscar Garza, deputy editor of the Los Angeles Times Magazine, said that when he was studying journalism at the University of Texas in the mid-1970s, an organization of Chicano communications students held a conference, "and it was a big deal, even then, that Frank came out to speak to us."
"We knew how rare it was for a Chicano journalist to be working at a place like the L.A. Times," Garza said.
In 1998, Del Olmo was selected to lead the Latino Initiative, a newspaperwide effort to increase and improve coverage of Southern California's largest minority group.
Frank Sotomayor, a Times colleague who was co-editor of the Pulitzer-winning Latino series and had planned to have lunch Thursday with Del Olmo to talk about Latino news coverage, said, "Until the very end, he was dedicated to covering the Latino community better."
Del Olmo was born in Los Angeles on May 18, 1948. He graduated magna cum laude from Cal State Northridge in 1970 with a journalism degree. He went to work for The Times that same year.
State Assembly Speaker Fabian Nuñez (D-Los Angeles) said Del Olmo "was more than an editor or columnist; he was a powerful pioneering voice for Latinos, for immigrants and the less fortunate."
Del Olmo was a Nieman fellow at Harvard University in 1987-88 and was inducted into the National Assn. of Hispanic Journalists' Hall of Fame in 2002. In 1972, he was a founding member of the California Chicano News Media Assn. He also won an Emmy Award for writing "The Unwanted," a 1975 documentary on illegal immigration.
As a columnist since 1980, Del Olmo wrote on a wide range of topics, from immigration to baseball. A private and kind man who was courtly in his manner, Del Olmo was known especially for his principled stands on issues affecting Latinos.