Greenville, S.C. — Four college students killed in an Ocean Isle Beach house fire early Sunday morning were from upstate South Carolina.

Travis Lane Cale, 19;  Justin Michael Anderson, 19; Lauren Astrid Kristiana Mahon, 18 -- attended the University of South Carolina. Emily Lauren Yelton, 18, was a student at Clemson University. Yelton's death has been especially difficult for her identical twin-sister, Meredith.

“Half of me is gone. The only person I want to talk to is her,” Meredith said.

Yelton's parents said Tuesday night the tremendous loss they have suffered hasn't sunk in yet.

“It's like God put up a shield. We don't feel it yet,” mother Kim Yelton said.

Emily followed her high school sweetheart Travis to Ocean Isle Beach for a weekend retreat.

“I was having a difficult time yesterday and it was good to know they were together,” Meredith said.

Emily and Travis spent the early hours of Sunday morning hanging out with 11 friends at 1 Scotland St. They were asleep when a fire started just before 7 a.m.

Ocean Isle Beach firefighters were on the scene within minutes, but the house was fully engulfed in flames when they arrived. Seven college students were killed; six managed to escape.

The Yelton family said they found some comfort hearing from the medical examiner that each victim likely died in their sleep.

“She knows we loved her. We were really close,” said Kim Yelton.

Ocean Isle Beach Mayor Debbie Smith said investigators believe the fire was probably accidental.

Also killed in the fire were Cassidy Pendley, 18, of Charleston, S.C.; William Rhea, 18, of Florence, S.C.; and Allison Walden, 19, of Chagrin Falls, O.H.

Many of the 13 students at the house were members of the Sigma Alpha Epsilon fraternity and Delta Delta Delta sorority.

Clemson University has scheduled a prayer vigil Wednesday night. People were asked to wear white ribbons in honor of the fire victims.

At the University of South Carolina, students have been leaving flowers, hand-written notes and stuffed animals at a memorial.