(Creative Commons via JHoch)

Getty Images' Chris Hondros was also killed in the blast, and two other journalists were injured.

Hetherington was an acclaimed photographer whose work has appeared in the New York Times, Newsweek and the Economist. He was also a contributing editor at Vanity Fair.

He was the director and producer of the recent Afghan war documentary "Restrepo," which won the Grand Jury Prize at the Sundance Film Festival in 2010 and was nominated for an Oscar for best documentary in 2011.

Hetherington was remembered fondly by friends, colleagues and fans.

"I think a viewer of Tim's photos might feel that he was really in it with the soldiers—not just observing," Vanity Fair's photography director, Susan Smith, told the Wall Street Journal. "That sort of commitment combined with the artistry he brought to the end photograph was a powerful mix."

The Guardian's David Batty wrote, "I first met Tim while doing a postgrad in journalism at Cardiff University. He was the star student on the photojournalism course – everyone on the print courses wanted to work with him as he fast gained a reputation as a creative photographer with a knack of getting access to interesting people and situations."

Batty said Hetherington had a "mix of charm and compassion" that was "a great attribute in a job where you were often dealing with vulnerable, distressed, if not traumatised, individuals: young runaways, victims of abuse, the mentally ill and addicts. Whenever he accompanied you on a story there was little need to persuade interviewees to open up - people just dropped their guard."

In a statement to Vanity Fair, Hetherington's family said, "It is with great sadness we learned that our son and brother, photographer and filmmaker Tim Hetherington, was killed today in Misrata, Libya by a rocket-propelled grenade. Tim will be remembered for his amazing images and his Academy Award–nominated documentary 'Restrepo,' which he co-produced with his friend Sebastian Junger.

"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."

Huffington Post blogger Jon Chattman wrote about meeting Hetherington and "Restrepo" co-director Sebastian Junger at the Independent Spirit Awards, "When I interviewed both Hetherington and Junger, they seemed more excited to get the word out than any prize they were up for. Hetherington, in particular, struck me as a man who cared so deeply for the subjects he and Junger met in the trenches."

Vanity Fair editor Graydon Carter said his staff was stunned by the loss.

"We’re just devastated here,” Carter said. “But he lived for this. And this sort of thing did not faze him. It’s what gave him life, and it’s what took it away from him.”

Kenneth Roth, the executive director of Human Rights Watch, said, "This is a devastating loss to many of us personally. But it is also a devastating loss to the human rights community. His work has raised the visibility of many of the world’s forgotten conflicts. May the legacy of his exceptional photographs serve to inspire future generations.”

White House Press Secretary Jay Carney issued a statement Wednesday afternoon, "We were saddened to learn of the death of film director and photographer Tim Hetherington while working in Misrata, and we are deeply concerned about the well being of other 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. The Libyan government and all governments across the world must take steps to protect journalists doing this vital work. The United States will work to do everything possible to assist those who were injured in getting the care they need. Our thoughts are with these brave journalists and their loved ones."

Foreign Policy's Elizabeth Dickinson wrote that before she ever met Hetherington, he had already offered to help her, "Tim had become a giant in his field, he was more down to earth than most anyone. If he noticed how young I looked, back then, Tim never let on. He treated me like a colleague. That's the best tribute I can give him today, amid the terrible news of his passing. He was one of my first colleagues as a journalist working in Africa, and I'll always remember his kindness as an exemplar of what it means to be a compassionate human being in a place that demands the most from journalists."