Carbon monoxide leaked into a Roanoke College dormitory early Friday, sickening more than 100 teens and adults attending summer programs. One man was found dead.

People staying in the dorm contacted campus police, and one woman later described the scene inside as chaotic.

"One woman fell on the floor in the bathroom," said Annabelle Minter, 80, of Richmond. Minter said she also felt "on the dizzy side" and was taken to a hospital, but her roommate was even sicker.

Walter J. Vierling, 91, a retired pastor from Pearisburg, was found dead in a dormitory room, said college spokeswoman Teresa Gereaux. The medical examiner had not determined the cause of death.

Fire officials were trying to determine the source of the leak, and said they were focusing on a gas hot water system as a possible cause.

Of the 62 people taken to one of the hospitals, five were admitted — one in critical condition and the others in fair condition, said Candi Carroll, director of emergency services for Lewis-Gale Medical Center. The woman in critical condition was "awake, alert and responding," Dr. Robert Dowling said.

Carilion Roanoke Memorial Hospital had treated and released 49 people, spokesman Steve Munsey said. The patients, whose ages ranged from 15 to 82, were checked for carbon monoxide in their blood and given oxygen through face masks.

About 100 of the dormitory guests had traveled from across Virginia, North Carolina and Pennsylvania to attend Power in the Spirit, a three-day Lutheran conference. There were also 37 teenage girls from southwest Virginia staying there as part of the Upward Bound program, Gereaux said.

Those in the church group appeared to have been more severely affected because of where they were located in the dormitory, Dowling said.

Carbon monoxide is a colorless, odorless and tasteless gas that can cause sickness or death. Leaks in buildings typically come from furnaces, heaters and other gasoline-powered equipment.

Carbon monoxide poisoning is "essentially like drowning on the air," Dowling said.