PORTLAND – A memorial service was held Wednesday at the University of Southern Maine for a South Portland 20-year-old junior who drowned while hiking in the Philippines.

Kim Lim, a 2010 South Portland High School graduate, was studying for a semester in South Korea when the incident occurred April 28, said USM spokesman Bob Caswell.

Lim had taken a side trip with a group of friends to hike in the Philippines. They were in a remote area when he drowned near a waterfall.

“We still don’t know exactly how it happened,” Caswell said.

Lim was a star student, a Mitchell Scholar and recipient of USM’s presidential scholarship, and had graduated in the top 10 percent of his high school class.

He excelled as a student despite having immigrated with his parents and brother from Cambodia to the United States in 2008 and knowing almost no English when he arrived.