New York Times correspondent Anthony Shadid, a two-time Pulitzer Prize winner, has died in eastern Syria after slipping into the country to report on the uprising against its president.
Mr Shadid, 43, shot in the West Bank in 2002 and kidnapped for six days in Libya last year, apparently died of an asthma attack, the Times said. Times photographer Tyler Hicks was with him and carried his body to Turkey, the newspaper said.
"Anthony was one of our generation's finest reporters," Times publisher Arthur Sulzberger said in a statement. "He was also an exceptionally kind and generous human being. He brought to his readers an up-close look at the globe's many war-torn regions, often at great personal risk. We were fortunate to have Anthony as a colleague, and we mourn his death."
Mr Shadid's father Buddy said his son had asthma all his life and had medication with him.
"(But) he was walking to the border because it was too dangerous to ride in the car. He was walking behind some horses - he's more allergic to those than anything else - and he had an asthma attack."
The Times reported that Mr Shadid and Mr Hicks were recently helped by smugglers through the border area in Turkey adjoining Syria's Idlib province and were met by guides on horse-back.
Mr Hicks told the newspaper that Mr Shadid suffered one bout of asthma the first night, followed by a more severe attack a week later on the way out.
"I stood next to him and asked if he was okay, and then he collapsed," he told the Times.
He said Mr Shadid was unconscious and his breathing was "very faint" and "very shallow". After a few minutes, he said he could see that Mr Shadid "was no longer breathing".
Mr Shadid, an American of Lebanese descent who strove to capture untold stories in Middle East conflicts from Libya to Iraq, had a wife, Nada Bakri, a son and a daughter.
He had previously worked for the Associated Press, The Washington Post and The Boston Globe.
He won Pulitzer Prizes for international reporting in 2004, when he was with the Post, and in 2010, when with the Times, for his Iraq coverage.
In 2004, the Pulitzer Board praised "his extraordinary ability to capture, at personal peril, the voices and emotions of Iraqis as their country was invaded, their leader toppled and their way of life upended".
Mr Shadid was also the author of three books, including House Of Stone: A Memoir Of Home, Family, and A Lost Middle East, in which he wrote about restoring his family's home in Lebanon.
Mr Shadid was a native of Oklahoma City and graduated from the University of Wisconsin-Madison. He joined the AP in Milwaukee in 1990, worked on the international desk in New York and served as the AP's news editor in Los Angeles. He was transferred to Cairo in 1995, covering stories in several countries.
AP senior managing editor John Daniszewski, who worked with Mr Shadid in Baghdad during the US invasion in 2003, called him "a brilliant colleague who stood out both for his elegant writing and for his deep and nuanced understanding of the region".
"He was calm under fire and quietly daring, the most admired of his generation of foreign correspondents."