Award-winning war photographer Tim Hetherington was killed today in the Libyan city of Misrata, where rebels have been trying to hold off a brutal assault by the Libyan army. A statement from his family said he was killed by a rocket-propelled grenade. A second photographer, Chris Hondros of Getty Images, has also died of wounds sustained in Misrata today.
In a message sent from his Twitter account yesterday, his first tweet in months, Hetherington wrote: "In besieged Libyan city of Misrata. Indiscriminate shelling by Qaddafi forces. No sign of NATO."
Hetherington went wherever there was conflict and danger, mindful of the risks, but determined to capture the truth of what he saw.
Our investigative unit was honored to have the chance to work with him. Hetherington's most memorable work was in Afghanistan in 2007 and 2008, on assignment for ABC News' "Nightline" and "Vanity Fair" magazine, along with reporter Sebastian Junger. Neither flinched under fire.
U.S. Army Major Dan Kearney, who was prominently featured in Hetherington and Junger's Afghanistan coverage, said that in his time with the troops, Hetherington became family.
"Tim wasn't just a friend," an emotional Kearney told ABC News after learning of Hetherington's death. "He was a brother to me."
On and off over 15 months, Junger and Hetherington followed one U.S. Army unit, Battle Company, in the dangerous Korengal Valley.
"There was certainly tension in the air," Hetherington said in 2007 of the experience. "One of the questions I asked everybody is an obvious question but I wanted to hear what they said -- 'Are you scared to go in there?'"
If he was scared, Hetherington never showed it.
On one mission, Battle Company got word that the Taliban was tracking them as they pulled back to their base.
Said Hetherington, "It was a sense that we were now going to be hunted. I think we were hunting and being hunted and that was not a great feeling."
There was chaos that day as the shooting began, and the adrenaline flowed, but Hetherington kept rolling on the soldiers, steady as always.
Hetherington filmed one of the soldiers as he described the feeling: "I'm the wrong one to play with," the soldier said. "I just miss the firefights, it's been awhile for me. I'm like a little kid right now. It's just a good time. This is what we get paid to do right here."
But then came word that the advance scouts had been hit.
Under fire, the men, Hetherington right with them, rushed to the scene.
"And we ran up to the ridge expecting there to be fighting," recalled Hetherington, "and instead we came across the scene of the scouts and of part of the second platoon that had suffered casualties."
There was a grim discovery involving a company leader, Sergeant Larry Rougle.
"I saw that Sgt. Rougle had been shot," Hetherington said. "And I saw there was just pandemonium. It really was an awful sight, it was a really hard sight to digest. Where men are just in such a state of shock, I think I was in a state of shock too."
The men were distraught, and as close as he was to them, he did not hesitate to do his job as a journalist while the platoon lieutenant got his men back into the battle.
"I was really amazed by the maturity and that he was to just grab this guy and the guy suddenly just came back to life," said Hetherington. "In that way, he was suddenly alert and ordering people around. Somebody so in the grip and suddenly snapped together."
There was no time to grieve, added Hetheringon, "because suddenly it was like the combat was back on."
Hetherington chose to stay with Battle Company as made their way back to the base that night. When he broke his ankle coming down a steep mountain, forced to walk in on it.
Hetherington and Junger's footage and reporting for "Nightline" won the Overseas Press Club award and a DuPont Award from Columbia University.
Hetherington seemed almost embarrassed to accept an award that documented the heroism of others, dismissing those who called him a hero too.
The footage was later edited into a feature documentary called "Restrepo", which was nominated for an Academy Award this year.
But the awards and honors meant much less to him than the work itself.
And it wasn't long before Hetherington was on to his next assignment, Libya, where he was killed Wednesday at the age of 40.
In their statement, Tim's family noted that Hetherington would be remembered for his "amazing images" and his journalism, and said, "Tim was in Libya to continue his ongoing multimedia project to highlight humanitarian issues during time of war and conflict. He will be forever missed."
President Barack Obama said in a statement he was "saddened" to learn of Hetherington's death and said he is "deeply concerned about the well being of journalists who were wounded alongside him.
"Journalists across the globe risk their lives each day to keep us informed, demand accountability from world leaders, and give a voice to those who would not otherwise be heard," he said.
Two other photographers were also wounded during the attack in Misrata Wednesday. Guy Martin of Panos News Agency was gravely wounded, while photographer Michael Brown was less severely wounded.
ABC News' Martha Raddatz contributed to this report.