SACRAMENTO (CBS13) — When planes hit the World Trade Center nearly 20 years ago this week, thousands of people ran from Manhattan to escape the collapse. But first responders, including a Sacramento firefighter, ran toward the danger to search for survivors.

“I lost a really good friend. He was a New York City fireman. His name is Dana Hannon,” said Chris Costamagna, deputy chief of the Sacramento Fire Department.

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Dana is engraved in the memory of Costamagna and on an engraved metal bracelet around his wrist.

“You don’t forget about him, you never forget about him,” Costamagna said.

But he has memories from September 11, 2001, that he wishes he could forget.

“We didn’t find anybody alive,” he said.

Just hours after the towers fell, Costamanga loaded onto a C-17 at the Travis Air Force Base in Vacaville, deploying with Sacramento’s Urban Search and Rescue team to ground zero. It was one of the only planes allowed to fly.

“The fastest cross-country flight I’ve ever had,” Costamagna said.

Fighter jets escorted the military aircraft into New Jersey, and the team got to work.

“As we were moving into Manhattan, we had to move police cars out of the street,” Costamagna said.

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Nothing could have prepared him for what he saw.

“A punch in the gut was seeing a plane hit the building. The punch in the face was standing at Church and Vesey [streets] and seeing a hundred-and-ten-story building reduced to five stories,” he said.

Sacramento’s USAR team did what they could to pull bodies from the piles.

“What we were finding was part of a person,” Costamagna said. “But that became very important because that identified people in the coming months.”

Costamagna said those are memories that stick with you.

“Twenty years later, I’m stronger. There was a time when I needed help and I didn’t seek it out right away, and I didn’t realize how much stronger and healthy I could be until I sought it out—and I did that,” he said.

He still thinks of that day and the days that followed.

“NYC was back on its feet and working,” he said.

But what stays with him the most? The memory of his friend Dana Hannon. Costamagna said he would want his friend to know some things.

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“I’d tell him I love him and I appreciate him and the job he does and that he’s everybody’s hero,” he said.