Andrew Breitbart, Conservative Blogger, Dies at 43 He was 43. Among Mr. Breitbart's targets was a New York congressman, Anthony Weiner, who ultimately resigned over explicit photographs he sent to women via Twitter and Facebook that were published on Mr. Breitbart's Web site. Lt. Larry Dietz, watch commander for the Los Angeles County Coroner's Office, confirmed Mr. Breitbart's death on Thursday. Ed Winter, a spokesman for the coroner's office, said Mr. Breitbart was found "evidently collapsed" but would not say where. Paramedics responded and transported him to the U.C.L.A. Medical Center, which reported that Mr. Breitbart had died just after midnight. "He does have some medical history issues, but he hadn't seen a doctor in the last year or so," Mr. Winter said. He would not say exactly what those medical issues were, but said the coroner's department was investigating and he would probably have more information later in the day. Mr. Breitbart's father-in-law told The Associated Press that he was walking near his home in Los Angeles when he collapsed. The news spread on Twitter, where followers of the conservative blogger expressed surprise that the larger-than-life Internet presence had died. "Absolutely stunned to hear about Andrew Breitbart," Brad Dayspring, a spokesman for Eric Cantor, the majority leader in the House, wrote on Twitter. At the top of Drudge Web site, was the following note to readers: In the first decade of the DRUDGEREPORT Andrew Breitbart was a constant source of energy, passion and commitment. We shared a love of headlines, a love of the news, an excitement about what's happening. I don't think there was a single day during that time when we did not flash each other or laugh with each other, or challenge each other. I still see him in my mind's eye in Venice Beach, the sunny day I met him. He was in his mid 20"s. It was all there. He had a wonderful, loving family and we all feel great sadness for them today... In 2009, Mr. Breitbart started the first in a series of "Big" blogs with names like "Big Journalism," "Big Hollywood" and "Big Government." Mr. Breitbart relentlessly attacked what he called liberal bias in the media, though he frequently consented to interview requests from the news outlets that he labeled that way. Once, when he was pitching a story idea to a reporter at The New York Times, he playfully wrote in the subject line of the e-mail, "Am I off-limits?" though he knew he was not. Mr. Breitbart earned a reputation for being playful but also highly polarizing; in an infamous case in 2010, he helped to instigate the firing of an Agriculture Department official, Shirley Sherrod, by publishing a misleading video clip of her speaking. At the time of his death, she was suing him for defamation. He was vilified by liberals who believed that he coarsened the public discourse. He often found ways to make himself the center of attention - as when he showed up at a news conference arranged by Mr. Weiner last June and started taking questions from journalists. The news conference was sparked by Mr. Breitbart's publishing photos of a bare-chested Mr. Weiner on his site BigGovernment.com; the ensuing scandal over Mr. Weiner's online contacts with women via Twitter and Facebook led to Mr. Weiner's resignation days later. But he was admired by many conservatives. Michelle Malkin, a conservative blogger and television commentator, wrote in a blog post Thursday that his legacy "online and in the conservative movement is built to last." A reporter traveling with the Republican presidential candidate Rick Santorum said that Mr. Santorum was visibly shaken when asked about Mr. Breitbart's death. He called the death a huge loss for the country and the conservative movement. Ian Lovett contributed reporting from Los Angeles.