"While all details are not yet available, we do know that as the group made its way out of the water and onto the shore, Nate was not among them," Dickinson president William G. Durden wrote in an e-mail to students, faculty and staff on Sunday afternoon.
A search ensued, and Kirkland's body later was found on the beach by authorities, said Christine M. Dugan, a Dickinson spokeswoman.
The e-mail sent to parents said the trip "was a chance for Nate to further his commitment to community service; his willingness to help others will be missed terribly. . . . Nate touched many of our lives, and his sudden loss comes as a shock."
A tribute page to the student, a graduate of Central High School, had garnered more than 600 hits on Facebook as of late yesterday afternoon.
Kirkland was a residence-hall adviser, founder of Dickinson's multimedia club and a member of service organizations.
"It's really tragic, and a lot of students are very upset," Dugan said. "We're offering counseling and everything we can to support them."
The spring semester resumes Monday.
Dugan said 18 individuals, including Kirkland and three staff members, left for the trip on Jan. 5 and were due to return Thursday. Dickinson is trying to bring the group back sooner, she said.
Contact staff writer Susan Snyder at 215-854-4693 or ssnyder@phillynews.com.