NEW YORK (WLNY) – Just over two years ago, a deadly shooting almost took the life of Congresswoman Gabrielle Giffords.

But her young aide’s quick actions helped save her life — a fact acknowledged by President Obama.

Now, Daniel Hernandez has gone from reluctant hero to author of a memoir. His new book, “They Call Me A Hero” is out this week.

More: First Photos Of Gabrielle Giffords After Shooting Released

He shared details of that day January 8, 2011 while visiting The Couch.

“At first I thought it may have been, potentially fireworks,” Hernandez said of the shooting. “By the second or third shot, someone yelled the word ‘gun’ and I dropped immediately what I was doing.”

Hernandez rushed to Giffords and others who had been wounded.

“I knew that with the limited medical training I had I probably had more training than anyone else there in the immediate area,” When you have gun shot wounds that are so severe, it’s a matter of seconds not a matter of minutes that make a difference.”

The 22-year-old is completing his senior year at the University of Arizona.