PASADENA, Calif. - They say photographs are a window into the past.

And on the 30th anniversary of the Tiananmen Square massacre, Catherine Bauknight’s photos of that tragic day provide a perspective that few can.

“They asked me and motioned for me to (she makes a gesture to snap a photograph) they would go, ‘For the free world,’” Bauknight said.

She was one of only four photographers to capture the brutal crackdown on the historic democratic protest that left approximately 3000 people -- mostly Chinese students -- dead, and thousands more injured.

Her photos paint a graphic picture.

She remembers the surreal moment when -- after a voice over the loudspeaker told demonstrators to evacuate or risk deadly force -- gunfire erupted.

“We just looked at each other and said, ‘These people are hysterical,’ thinking they’re going to shoot at them. And just going on our way, but then we did hear the popping. And then we just, it was a quick awakening,” said Bauknight.

But the story behind each photo speaks to the moment in history.

Tiananmen Square brought the boom down on China's 1989 Democracy Movement, that had been going on for seven weeks.

Demonstrators trying to block military tanks and troops with assault rifles were protesting communism and martial law, which had silenced freedom of speech, press and democratic values.

“They were content to know that they would possibly die from this or they would be wounded or just the opportunity that presented itself for them to talk about and represent their vision of democracy,” said Bauknight.

Bauknight was ushered through the chaotic scene by a human tunnel -- protesters recognizing her ability to capture the moment and tell the world. With phone lines cut off and only one airline still flying, a French photographer met her and got the images onto an Air France flight -- the rest of her footage she smuggled back into the U.S.

“Nobody was supposed to know I had the film, and not even the people around me. Nobody should know because they could turn me in,” Bauknight said.

Now, 30 years later, these photos are just as powerful -- documenting a tragedy -- in the hopes of history never repeating itself.