– Subway co-founder Fred DeLuca died Monday evening after being diagnosed with leukemia two years ago, the company said Tuesday. He was 67.

DeLuca’s death came weeks after the 50th anniversary of Subway, which is the world’s biggest restaurant chain by locations with more than 44,000. The company traces its roots to 1965, when DeLuca opened a sandwich shop at the age of 17 to help pay for college after graduating high school. The idea came from a family friend, Peter Buck, who was a co-founder and provided the $1,000 to start the business.

“I knew nothing about making sandwiches, nor the food industry,” DeLuca later wrote in a book.

DeLuca and Buck opened their first store in Bridgeport, Conn., under the name “Pete’s Super Submarines,” with the priciest sub selling for 69 cents. The name was changed to the snappier “Subway” in 1968, and the pair decided to fuel growth by franchising.

By 1988, Subway had 2,000 locations. By 1990, it reached the 5,000-store mark. And by 1994, it had more than 8,000 locations.

Subway, based in Milford, Conn., is privately held and provides few glimpses into its inner workings. But in July 2013, the company announced that DeLuca had leukemia. It said DeLuca was in regular contact with his management team, but on a reduced basis as he received treatment.

Then earlier this summer, Subway said DeLuca’s younger sister, Suzanne Greco, would take over as president and oversee day-to-day operations. DeLuca remained CEO.

Associated Press