When a Colombian volcano erupted in 1985 and killed more than 20,000, Carol Guzy trudged through miles of mud to capture images of the tragedy. This effort won her and her Miami Herald colleague their first Pulitzer Prize for spot news photography, reports CBS News correspondent Jan Crawford.

Nearly 10 years later when U.S. troops entered the impoverished island nation of Haiti, Guzy’s images for the Washington Post again brought the faraway conflict to people back home and earned her a second Pulitzer. She went on to become the only person to have received four of the prestigious awards for journalism.

But growing up poor in Pennsylvania, Guzy had no idea what a photojournalist was and wanting a stable career, she studied to be a nurse. When a friend gave her a camera, she found her calling and purpose.

She has traveled the globe, seeking light during the darkest tragedies. Some of her Pulitzer-winning photographs have become iconic.

“I don’t believe the Pulitzers belong to us, I think we just accept them for the people that are in our stories. They’re the courageous ones and they’re the ones who’ve opened up their lives so that we could take those pictures and tell their stories,” Guzy said.

To capture those powerful moments, Guzy tries to connect with the people in her photographs to imagine their suffering.

“I definitely have an overdose of empathy, I think that’s probably the key word to make compelling images,” Guzy said.

In 1999 when tens of thousands of ethnic Albanians fled violence in Kosovo, Guzy traveled to the border and captured images of hope and heartache that earned her and her team a third Pulitzer, but the experience brought her to an emotional breaking point.

“I felt so guilty that I’d be able to get on a plane and leave a lot of these places and… the people were stuck in their reality long after the headlines were gone,” Guzy said. “But I think you learn to cope by realizing that it is a mission, it’s not just a job.”

After a leave of absence, Guzy returned to the post and again began traveling the world covering humanitarian conflicts from India to Ethiopia and making friends along the way.

A photo story on child amputees from Sierra Leone resulted in a number of adoptions, including a young girl named Mamuna who became Guzy’s goddaughter. Again and again she returned to Haiti and when the country was ravaged by an earthquake in 2010, it shook Guzy to her core.

“I loved the people and I loved the spirit and it was like my second home almost, so when the earthquake happened it just about destroyed me,” Guzy said.

Guzy’s coverage of the recovery effort earned her and her colleagues a historic fourth Pulitzer. Her pictures now hang alongside hundreds of other Pulitzer Prize-winning images at the Newseum.

The pictures are a testament to the power of images to change history. Pictures like Kevin Carter’s 1993 picture of a starving Sudanese girl or William Beall’s 1957 picture of a policeman talking with a young boy.

Guzy’s photographs often show hope even in the darkest of circumstances. It’s what she searches for when she arrives in a place like Haiti.

When asked how she keeps going after taking these kinds of photographs, Guzy answered, “I tend to always look for those moments of hope too because I think we need balance. We need to show people not only the problems, but sometimes the solution too. And it saves my faith in humanity for sure.”

In that way, these photos can effect change. To a journalist like Guzy, that’s the real reward.

“For me anyway it’s always been my life and a calling of sorts to, you know, to make people aware and every now and then things do change. Maybe slowly and incrementally, but pictures can make a difference I think,” Guzy said.

For a journalist, the Pulitzers are the highest honor. The winners of the 2017 Pulitzer Prizes will be announced today at Columbia University in New York.