A carbon-monoxide leak forced the evacuation of a Roanoke College fraternity house this past weekend. Residents were awakened by a detector installed after a deadly leak in a dormitory in July, school and fire officials said.

The July carbon-monoxide leak killed an elderly man and sickened more than 100 others. No one was injured in Saturday’s leak.

Salem Fire Department officials responded to the Sigma Chi fraternity house at 1 a.m. after a resident called campus safety because the carbon-monoxide alarm was going off. Campus officials evacuated seven people from the house, college spokeswoman Teresa Gereaux said.

Fire officials later tied the leak to a clogged flue pipe in the boiler system, Salem fire Lt. John Prillaman said.

School officials were relieved by quick student response. “It is reassuring to know that the safety measures we implemented this summer are working,” Sabine O’Hara, president of the college, said in a news release.

On July 14, 91-year-old Lutheran pastor Walter J. Vierling died when carbon monoxide filled the college’s Sections dorm building, where he and others were staying with a Lutheran conference and teenagers were being housed for a summer college preparatory program. That leak sent 114 people to two hospitals.

Investigators later connected it to a failure in a natural-gas-powered water-heating system.