Updated

Well-known columnist and editor Michael Kelly was killed Thursday night while traveling with the Army's 3rd Infantry Division in Iraq.

He was the first American journalist to die in the war.

Kelly is believed to have been traveling in a humvee when it suddenly veered off the road and fell off a cliff into the river below. The vehicle may have been fired upon by Iraqi military and possibly disabled before it fell.

"He was just an extraordinarily brilliant and capable guy," Fox News Sunday anchor Tony Snow said Friday. "There aren't many people who on a regular basis, when I'm reading their columns, I say 'man, I wish I'd written that.'"

Calling him "one of the handful of editorial geniuses in our generation," Snow described the tragedy as "an indescribable loss to the journalism profession.

"There aren't that many people who make that kind of an impact in so few years," as Kelly did, he said.

Kelly was the editor-at-large for the Atlantic Monthly and a Washington Post columnist. He previously served as editor of the New Republic and National Journal.

The 46-year-old was the first journalist to die among the 600 embedded with the U.S. armed forces. Journalists trained to go to Iraq with military forces to give America a first-hand account of Operation Iraqi Freedom.

Washington Post media columnist Howard Kurtz notes that Kelly was quoted in the New York Times four days ago as saying that he and other reporters enlisted in the Pentagon program because "there was a real sense after the last gulf war that witness had been lost. The people in the military care about that history a great deal, because it is their history."

Kelly was fired in 1997 by New Republic owner Martin Peretz -- who was pals with former Vice President Al Gore -- as the magazine's editor over his continuing attacks on the Clinton administration.

He then became a columnist for the Post and was hired as the editor of National Journal, the weekly magazine that covers the federal government.

Kelly became editor-in-chief of The Atlantic Monthly in 1999 after Mort Zuckerman sold the 140-year-old publication to David Bradley. Salon.com described him then as "perhaps best known for his short, stormy tenure as editor of the New Republican and his Clinton-bashing editorials in the Washington Post."

The Atlantic Media Company, owned by Bradley, is the parent company to The Atlantic Monthly and National Journal Group. National Journal Group also includes National Journal magazine -- where Kelly was an editor -- Congress Daily, The Hotline, Technology Daily, Government Executive and American Health Line.

"This is the first friend and the best friend I made in journalism … he can't be touched," Bradley said in a statement Friday. "He is loved by everyone at The Atlantic, by everyone at the National Journal, by everyone at the places we worked together.

"The Atlantic has had 145 years of good times and bad, but no moment more deeply sad than this one now."

"He saw his profession not as a game but as a public service," said Atlantic Managing Editor Cullen Murphy. "I want Mike's boys Tom and Jack to know that their dad was a hero. His loss is devastating to all of us."

"Some people knew Michael as one of this country's most gifted writers and editors," Atlantic Media Group President John Fox Sullivan said in a statement. "Many knew him as a fiery columnist. I knew him as an honest, funny, caring and even gentle human being. He was one of a kind who will be sorely missed and never forgotten."

"I can say that he was a hell of a guy," Technology Daily assistant editor Shawn Chen told Foxnews.com. "I met him once, recently, and man ... the stories he told really made you feel proud to be a journalist.

"I think the profession as a whole will be a little more empty without Michael [Kelly]."

"Mike was just a phenomenal journalist with an enthusiasm for his work that was surpassed only by his love for his family," said Pentagon spokeswoman Victoria Clark.

The Atlantic won three National Magazine Awards last year, including one for excellence in reporting and carried many high-profile cover stories, including a three-part series on the cleanup of the World Trade Center site, Kurtz notes.

Kelly stepped down as editor last fall but stayed on as editor-at-large and continued as chief editorial adviser to National Journal.

A Washingtonian growing up, Kelly was the son of Thomas Kelly, a reporter for the now-defunct Washington Daily News. His mother, Marguerite Kelly, is the author of a syndicated column called "Family Almanac."

His Iraq reports ran in numerous newspapers. His last column ran on Thursday and was entitled, "Across the Euphrates."

In the first Gulf War, he was one of the few reporters in Baghdad during the first 24 hours of the bombing and was in the first group to reach Kuwait City within hours of its liberation, according to his biography.

Kelly landed a job in 1979 with ABC's Good Morning America, first as a researcher, then as a news booker and associate producer. He left after four years and took a job at the Cincinnati Post, where his stories won numerous awards from the Associated Press, Sigma Delta Chi, United Press International and others.

In 1986, he joined the Baltimore Sun and soon became a Washington correspondent, where he covered the Iran-contra affair and the presidential campaigns of Jesse Jackson and Michael Dukakis.

In 1989, Kelly worked as the Midwest stringer for the Boston Globe and wrote articles for various magazines covering the Gulf War.

Soon after that, he walked for nine days from Iran into northern Iraq territory held by Kurdish rebels against Iraqi forces. He returned to Baghdad to report on life there after defeat. His work on this topic won him various awards.

Kelly went to work for the New York Times in 1992 as a Washington correspondent and covered the presidential campaigns of Ross Perot and Bill Clinton. The following year he became a staff writer for the New York Times Magazine, where he wrote cover stories on Clinton, Hillary Clinton and David Gergen. He spent the summer of 1994 in the Gaza Strip.

He joined the New Yorker in late 1994 as Washington editor and author of the "Letter from Washington" column. He spent the summer of 1995 in Bosnia and Croatia reporting on the fighting there and later covered the presidential campaign. Just after the election, he became editor of the New Republic and writer of its TRB column.

Kelly lived in Ballston, Va., and is survived by his wife, Madelyn and two sons, Tom, 6, and Jack, 3.

The Associated Press contributed to this report.