So far, Handschuh has been able to find every other person who assisted him on that fateful day in 2001, all but one.
"Nineteen years, 11 months 364 days later. I don't know who that firefighter is. I'd love to hug him. I'd love to say thank you. I hope he's safe. I hope he's alive," Handschuh said.
Handschuh was a photographer for the New York Daily News at the time.
He wasn't scheduled to work until later that day, but he happened to be in his car that morning.
"All of a sudden the police and fire radio started screaming. A plane has hit the World Trade Center and it's on fire," Handschuh said. "I looked up and saw the hole in the side of the building and went right down there."
Handschuh was standing in front of the South Tower when the second plane struck it.
He said he knew it was dangerous, but he kept working, recording history until he heard the rumble of the North Tower as it came crumbling down.
"For the first time in my career, I actually ran away from an assignment," Handschuh said. "I got picked up by a tornado of darkness, of building parts, of broken glass and debris, and I was tossed about half a city block. I was buried alive."
He was able to clear the choking dust from his mouth and nose and scream for help, but his leg was severely injured.
Firefighters heard him calling and quickly came to dig him out, but they left him there on the street.
That was Lieutenant Tom McGoff from engine 217 in Brooklyn and his crew, they were searching for two of their own that were lost.
Then, another crew of firefighters, Phil McArdle and Jeff Borkowski from Engine 288 in Queens found and him and carried Handschuh to where they thought was out of harm's way, until the second tower collapsed.
"A police officer named Jim Keller threw himself on top of me while I was lying on the floor," Handschuh said. "Without any regard to his safety, protected me when I was the most vulnerable."
This is where the mystery begins, Keller, EMS paramedic chief Charlie Wells and a third man, a firefighter, picked him up and started carrying Handschuh to safety.
"He might be a New York City firefighter. He might be a volunteer firefighter who came in and grabbed a coat. It might have been his personal equipment that he kept in a car," Handschuh said. "Who is this guy? Where is he?"
Handschuh has sent a picture of himself being carried by the three men to the firefighters' unions and the fire department directly, and it has been widely distributed on the internet, but no one has come forward or been able to recognize him.
"Terry Tobin was a police captain at the time. And she held my hand in the ambulance, go into the hospital, and called my family and told them that I was alive and we talk regularly. Every single-rescuer I'm still in touch with... where is this firefighter?" Handschuh said.
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