On 9/11, 27-year-old Jason Thomas was dropping off his daughter to his mother in Long Island.
When Thomas heard what had transpired, he changed into the Marine Corps uniform he had sitting in his trunk — he was a former sergeant who had been out of the Corps for a year — and sped toward Manhattan.

“Someone needed help. It didn’t matter who,” Thomas told AP. “I didn’t even have a plan. But I have all this training as a Marine, and all I could think was, ‘My city is in need.'”

Around the same time in Wilton, Connecticut, Dave Karnes was working in his office at Deloitte watching the event unfold on TV.

“I’m going there”, the former Marine staff sergeant said to his colleagues, before telling his boss he might not be back for a while, according to Slate. He went and got a haircut, changed into his Marine uniform, and drove toward New York City at 120 miles per hour.

Once both Marines reached the towers — the site now covered in ash and debris — they began searching for survivors, but first, they found each other. They had little gear with them besides flashlights and a military entrenching tool, AP reported.

Along with other first responders, the pair climbed over the dangerous field of metal, concrete, and dust, calling out, “United States Marines! If you can hear us, yell or tap!”

According to Stripes:

When they reached a depression in the rubble of what had been the south tower, he said, “I thought I heard someone. … So I yelled down and they replied back that they were New York Port Authority police officers. “They asked us not to leave them.”

Karnes told Thomas to get to a high point to direct rescuers to the site, then called his wife and sister on his cell phone and told them to phone and give the New York police his location.

The two officers, William Jimeno and John McLoughlin, were on the main concourse between the towers. They were alive, trapped approximately 20 feet below the surface.

According to USA Today, once they heard the voices of the Marines, Jimeno began shouting the code for officer down: “8-13! 8-13!” After they were located amid the unstable mountain of debris, it took rescue workers roughly three hours to dig out Jimeno, and another eight to reach McLoughlin, who was further down.

An exhausted Thomas, who never gave his first name, left the site after Jimeno was rescued, but returned to Ground Zero for the next 2 1/12 weeks to help. His identity was a mystery until after Oliver Stone’s 2006 film “World Trade Center” chronicled the rescue of the officers, and Thomas emerged from the shadows.

Karnes also left after Jimeno came up, but helped at the site for another nine days. After he returned to Connecticut, he went to his reserve center and reenlisted, and later served two tours of duty in Iraq.