(CNN) Like many people in New York, Hakki Akdeniz was taken aback when he heard about the brutal killing of four homeless people in the Chinatown neighborhood of Manhattan last week.

After he heard the news, he rushed to the area where the bodies were found, blood still visible on the ground.

"I was just shocked," said Akdeniz, who was once homeless himself.

Since the tragedy, he's visited the site daily, leaving candles and flowers in memory of the men that died, and a stack of boxes with fresh pizza for the homeless people in the neighborhood.

At his memorials, Akdeniz left a heartfelt letter, expressing sympathy for the community and sorrow that he wasn't there to protect the men who were killed.

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