The Los Angeles Times won this year’s top Pulitzer Prize for ferreting out government corruption in the poor, working-class city of Bell, Calif., it was announced Monday at Columbia University.

The series, led by reporters Jeff Gottlieb and Ruben Vives, triggered legislative reform, criminal charges against officials — including a city administrator who pocketed a nearly $800,000 annual salary — and millions in tax refunds to residents of the city in Los Angeles County.

It was the Times’ sixth public-service medal in the Pulitzers’ 94-year history, putting it one ahead of the New York Times and the St. Louis Post-Dispatch.

A trio of Washington Post photographers won the Pulitzer for breaking-news photography for their coverage of the January 2010 earthquake in Haiti. Carol Guzy, Nikki Kahn and Ricky Carioti were cited for “their up-close portrait of grief and desperation” captured over months. Guzy landed in Port-au-Prince 24 hours after the quake, as Haitians texted for help while trapped beneath rubble. Kahn made several trips over the ensuing months, as unrest and cholera festered, and Carioti arrived in August to document the continuing tragedy.

Thirteen honors for journalism were spread over 10 newspapers.

For the first time, a Pulitzer was awarded to written journalism that appeared exclusively online: “The Wall Street Money Machine,” by Jesse Eisinger and Jake Bernstein of the nonprofit investigative enterprise ProPublica, won for National Reporting.

The Los Angeles Times won a second Pulitzer on Monday for the feature photography of Barbara Davidson, who chronicled innocent victims of gang violence. The New York Times also won two Pulitzers, for “Economic Scene” columnist David Leonhardt’s commentary on the federal budget and health-care system, and for Clifford J. Levy and Ellen Barry for their international reporting on Russia’s justice system.

The prize for investigative reporting went to Paige St. John of the Sarasota Herald-Tribune for her examination of Florida’s property insurance system. The local reporting award was given to three Chicago Sun-Times reporters for documenting violence in Chicago neighborhoods.

Amy Ellis Nutt of Newark’s Star-Ledger won in feature writing for her report on the sinking of a commercial fishing boat that killed six men. Sebastian Smee of the Boston Globe won for his art criticism.

Joseph Rago of the Wall Street Journal won the editorial writing prize for challenging President Obama’s shepherding of health-care reform, and the editorial cartooning prize went to Mike Keefe of the Denver Post.

The Milwaukee Journal Sentinel won for using “words, graphics, videos and other images” in its explanatory-reporting entry on genetic technology.

Post Executive Editor Marcus Brauchli described the work of Guzy, Kahn and Carioti as “iconic” and an “amazing torrent of images that defined the event for so many people.” He also noted that Guzy’s fourth prize puts her in the same Pulitzer league as Robert Frost and Eugene O’Neill (who each received four Pulitzers in the “letters, drama and music” branch of the prizes, also awarded Monday).

Guzy, who joined The Post in 1988, has an impassioned, decades-spanning relationship with Haiti. She won the 1995 prize for breaking-news photography for covering the U.S. military intervention in Haiti for The Post.

“There’s an intensity there I’ve never found anywhere else — the beauty and the horror is something that brings you to your knees,” Guzy said. “There were so many little tragedies amidst the big tragedy, and yet I’ve never seen anything like a Haitian smile anywhere. How do they manage to keep that spirit in the face of adversity?”

Guzy, 55; Kahn, 43; and Carioti, 42, trained their cameras on desperate scenes: rubble, bodies, squalid hospital conditions, a crushed schoolgirl still at her classroom desk — images that rankled some readers objecting to the graphic nature.

“In this instance, we felt the power of the images conveyed not only the sheer force of the earthquake, but also the difficulty the people of Haiti and the world had in coping with it,” Brauchli said.

The Post also had two Pulitzer finalists, in the categories of editorial writing (Deputy Editorial Page Editor Jackson Diehl, for his articles on foreign affairs) and in explanatory reporting (for a multimedia series on advances made in military trauma surgery).

No breaking-news award was given, meaning that the 16 voting members of the Pulitzer board could not reach a majority vote on any one of the three finalists in the category.

“It kind of sticks out like a sore thumb for the business,” said Roy J. Harris Jr., a former journalist and author of “Pulitzer’s Gold: Behind the Prize for Public Service Journalism.” “This has happened several times before with other categories, but this category is the bread-and-butter of the business.”

Each Pulitzer, save for the public service medal, comes with a $10,000 prize.