Chris Sorensen, the former firefighter who turned Firehouse Subs into a billion-dollar sandwich empire alongside his younger brother, Robin, has died at 65. His death, reported earlier this month, comes as the company prepares to celebrate National First Responders Day with a new campaign honoring working K-9s—a cause closely tied to the legacy Sorensen spent decades building.

According to Fox News , Sorensen died October 11 at his home near Jacksonville, Florida. Firehouse Subs President Mike Hancock confirmed the news in a statement.

"We are deeply saddened by the passing of Chris Sorensen, co-founder of Firehouse Subs," Hancock said. "Our heartfelt condolences go out to his family, friends, and all who knew him."

Long before Firehouse Subs became a nationwide restaurant chain, Sorensen had an entirely different career.…