OCEAN ISLE BEACH — A fatal fire that killed seven South Carolina college students at an Ocean Isle Beach house likely started on the back deck, but the exact cause has not been determined, Mayor Debbie Smith said Friday.

Because of the extensive damage, it was impossible for investigators to uncover a definite cause, but they speculated that the blaze could have started from improperly discarded smoking materials, Smith said. She read from a report prepared by the State Bureau of Investigation and the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives.

"There has been absolutely no indication that the fire was intentionally set," Smith said.

Smith said investigators ruled out other sources, including the house's barbecue grill and outdoor fireplace.

"There have been no reports of any other sources of ignition within that area that could have served as a possible ignition source of the fire," she said.

Cassidy Fae Pendley, 18; Lauren Astrid Kristiana Mahon, 18; Justin Michael Anderson, 19; Travis Lane Cale, 19; Allison Walden, 18; William Rhea, 18; and Emily Lauren Yelton, 18, died in the Oct. 28, 2007, house blaze early Sunday morning at 1 Scotland St.

Six other students escaped the fire. All of the victims except Yelton were University of South Carolina students vacationing for the weekend. Yelton was a Clemson University student.

The North Carolina medical examiner said they died in their sleep from smoke inhalation and carbon monoxide poisoning.

Friday's preliminary report – the final report isn't expected to be released for several more weeks – also indicated survivors told investigators the house had smoke detectors and that they did activate, but it did not say how many alarms there were or where they were in the house.

All of the victims were on the second floor. All of the survivors, except one, were on the first floor.

Meanwhile Friday, President George W. Bush, in South Carolina for a political fundraiser, expressed his condolences and sympathies.

"I know people are hurting when they think about the seven youngsters who had so much hope in their lives and had their life taken during that fire," Bush said. "I hope the families and loved ones can take comfort that in this great state and around the nation there's a lot of people praying for them."

Services for Mahon and Yelton were held in South Carolina. Services for Walden, Cale and Anderson were scheduled for Saturday and for Pendley on Monday. Rhea's funeral was Thursday.

The University of South Carolina planned to hold a memorial service Wednesday at a campus theater to honor the students.

"Since learning the tragic news, students have been holding vigils and informal gatherings to express their grief," said Dennis Pruitt, the university's vice president for student affairs. "This ceremony will allow their families and the entire university community to come together to remember and celebrate the lives of these promising young people."

At the site of the fire, the charred structure and its property – deemed unsafe – were fenced off. In front stood a large metal cross with seven smaller ones adorned by bouquets of flowers and stuffed animals from passers-by.

Smith said Friday the community was still coping with the fire, which brought national attention to the small resort town of about 500 permanent residents and several thousand rental and vacation homes.

"We're still in mourning, and I imagine we will be for some time," she said. "Our hearts are still with the victims and their families. This is certainly a tragedy we hope we never have to deal with again."

The community has planned a special service to honor the victims Sunday morning at the Ocean Isle Beach Chapel, where families and friends gathered last week to receive news about their loved ones.