Mike O'Connor, a veteran war correspondent who became a tough advocate and counselor for threatened journalists in one of the world's most dangerous countries for the press, has died. He was 67.

O'Connor, the Mexico representative of the Committee to Protect Journalists, died in his sleep at his home in Mexico City on Sunday. The cause was a heart attack, according to his wife Tracy Wilkinson, who is bureau chief for the Los Angeles Times.

Local journalists and colleagues remembered O'Connor as a man with an unparalleled grasp of the perils and complexities of working as a journalist in Mexico. Hard on those he felt were failing to protect reporters, O'Connor showed boundless sympathy for journalists struggling to maintain careers and personal lives in the face of threats.

"He would spend hours over the phone with local journalists in the most isolated places in Mexico, just to listen to the stories and to try to help them cope with fear," said Carlos Lauria, senior Americas program coordinator for the New York-based nonprofit where O'Connor had worked since 2009.

Born in a refugee camp where his father was stationed in post-war Germany, O'Connor lived along the U.S.-Mexican border with his parents, often moving between the two countries on short notice, a childhood he described in a 2007 memoir, "Crisis, Pursued by Disaster, Followed Closely by Catastrophe: A Memoir of Life on the Run."

O'Connor worked as a television reporter in California, then covered Latin America during the 1980s for CBS News before moving into print, writing for The New York Times in Central America and the former Yugoslavia. He also reported for National Public Radio from Haiti, where he earned an Overseas Press Club award, the former Yugoslavia and the Middle East, where he covered the Israeli-Palestinian conflict.

"He was a journalist and this made him different from other members of groups that protect the press and freedom of expression," said Marcela Turati, a reporter who covers the drug war for the investigative news magazine Proceso. "He took defending journalists very personally."

O'Connor was one of the most important forces behind a 2012 Mexican law giving federal authorities greater powers to prosecute crimes against journalists in Mexico. The Committee to Protect Journalists says 29 have been killed in the country in retaliation for their work since 1992.

O'Connor's reporting skills and knowledge of Mexico allowed him to pierce the secrecy and ambiguity around many attacks and determine which had been motivated by the victims' work and which were unrelated.

At one press conference in the Pacific Coast state of Sinaloa, long dominated by a cartel of the same name, O'Connor issued a challenge to authorities, saying "Who's in control here? You or them? In the government, the governor's office, who's in control?" remembered Javier Valdez Cardenas, a correspondent for the Sinaloa paper Rio Doce.

O'Connor also made many trips to Mexican states where journalists were under daily threat, producing vivid, highly detailed reports on areas that were receiving little national or international attention.

O'Connor is survived by his wife, Tracy Wilkinson, two sons from a previous marriage, and two granddaughters, as well as two sisters and two half brothers.