A U.S. student who went missing while studying abroad in Italy was found dead inside a railroad tunnel in central Rome, police there said Saturday, CNN reported.

Investigators are looking into the death of John Durkin, an economics major from Rye Beach, New Hampshire, according to CNN.

The 21-year-old attended Bates College, but was one of six students from the Maine school taking part in a study abroad program in Rome through Trinity College in Connecticut, his school said, CNN reported. Both colleges are working with Italian authorities.

"It is with much sadness that the Durkin family informs you of the loss of John Nolen Durkin and thanks everyone for their support during the past few days," his family said in a statement released through Bates, CNN reported.

He's been in Rome for a little more than a month as part of a semester-long program, according to Tom Durkin, a family spokesman, CNN reported. Two days ago, he went to a bar with a group of friends and never returned, according to the spokesman, who said he left the bar alone.

Bates President Clayton Spencer expressed "deep sadness" for Durkin's death and saying his college shares "the tremendous grief of his family," according to CNN.

The U.S. Embassy in Rome also passed along its condolences to the family, CNN reported. Bates economics professor Margaret Mauer-Fazio recalled Durkin producing "nuanced, balanced and interesting" work on China's economic reform while in her class last fall, adding that "all his work was very strong."

The junior was also a linebacker on his college football team.

His head coach, Mark Harriman, recalled "John's commitment to excellence in all phases of his life (as) inspirational to the other members of the squad and a major factor in the team's success over the past three years," according to CNN.

"We will remember the fortitude and character that John displayed on a daily basis and attempt to emulate those standards," Harriman added.