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Cameraman Paul Douglas had spent more than a decade covering the world's hot spots for CBS News. Freelance soundman James Brolan was part of a CBS team honored for its dispatches on the earthquake in Pakistan. Correspondent Kimberly Dozier had reported on the deteriorating situation in Iraq for nearly three years.

The two British men were killed Monday in Baghdad when a car bomb exploded as they were working on a story about American troops in Iraq on Memorial Day. Douglas, 48, and Brolan, 42, died at the scene, the network said.

The U.S. military said an American soldier and an Iraqi interpreter were also killed in the same blast and six American soldiers were injured.

Dozier, 39, who is American, was in critical condition at a U.S. military hospital in Baghdad, said Kelli Edwards, a CBS News spokeswoman. By early Tuesday, Dozier was undergoing her second surgery for injuries from the bombing, Edwards said.

On Monday, doctors had said they were cautiously optimistic about her prognosis.

"Kimberly, Paul and James were veterans of war coverage who proved their bravery and dedication every single day," CBS News President Sean McManus said in a statement. "They always volunteered for dangerous assignments and were invaluable in our attempt to report the news to the American public.

"Our deepest sympathy goes out to the families of Paul and James, and we are hoping and praying for a complete recovery by Kimberly," McManus added.

CBS News reported on its Web site that the three journalists were embedded with the 4th Brigade Combat Team, 4th Infantry Division when a nearby car packed with explosives detonated, the network said.

All three journalists were believed to have been wearing protective gear at the time, CBS said.

A series of blasts killed at least 40 people Monday in Iraq and wounded dozens in the worst wave of violence to hit Baghdad in days.

Zalmay Khalizad, the U.S. ambassador to Iraq, said he was "shocked and saddened" by news of the journalists' deaths.

"These brave journalists risked their lives to tell the world the story of a courageous people and a proud nation," he said. "The terrorists who committed this evil crime have shown themselves for who they are. They do not want the world to see the truth of what is happening in Iraq, where a determined people are fighting for freedom and liberty. That story must and will be told."

Douglas, a British national based in London, had worked for CBS News since the early 1990s in places including Afghanistan, Pakistan, Rwanda and Bosnia. He is survived by his wife, two daughters and three grandchildren, CBS said.

Brolan, who also was based in London, had worked with CBS News during the last year in Iraq and Afghanistan as a freelancer. The British citizen leaves behind his wife of 20 years, Geri, and two children — 18-year-old Sam and 12-year-old Agatha.

"James had a natural way with people and was always in demand as the person to go with to the world's trouble spots; always putting the locals at ease, winning friends everywhere he went and always putting in his best effort," his family said in a statement. "He will be greatly missed."

In addition to her time in Iraq, Dozier also had worked as the chief correspondent for WCBS-TV New York's Middle East bureau in Jerusalem, and previously as London bureau chief and chief European correspondent for CBS Radio News.

Dozier graduated magna cum laude from Wellesley College, majoring in human rights and Spanish, according to her biography on the CBS News Web site. She later earned a master's degree in foreign affairs, specializing in the Middle East, from the University of Virginia.

Dozens of journalists have been injured, killed or kidnapped in Iraq since the 2003 U.S.-led invasion that toppled Iraqi dictator Saddam Hussein.

Before Monday's attack, the Committee to Protect Journalists had put the number of journalists killed in Iraq at 69. Of those, nearly three-quarters were Iraqis, the New York-based group said.

In January, ABC News anchor Bob Woodruff and cameraman Doug Vogt were injured while covering the war in Iraq. They were standing in the hatch of an Iraqi mechanized vehicle, reporting on the war from the Iraqi troops' perspective, when a roadside bomb exploded. Both were wearing body armor, which doctors say likely saved their lives.

Woodruff, who co-anchored "World News Tonight" with Elizabeth Vargas, is still recovering from serious head injuries. ABC News announced last week that Charles Gibson will take over as "World News Tonight" anchor.