The thunderstorm that blew through Notre Dame's campus Saturday disrupted power to about 40 percent of the University's electric system - leaving some students in the dark for up to 30 minutes.
The outage affected various buildings including several residence halls and the Main Building around 3:50 p.m., Notre Dame Director of Utilities Paul Kempf said.
No outages were reported at Saint Mary's, SMC Director of Facilities Rick Linio said.
The outage occurred when lightning struck an American Electric Power power line, Kempf said. The University receives nearly half of its power supply from AEP.
"AEP had an fault on their transmission line, and we disconnected from them, resulting in a need to interrupt power service to a portion of campus equal to that being supplied by AEP," Kempf said.
Kempf said the utilities department prioritizes which buildings on campus get outage protection depending on the time of day, day of the week or special events. Since the outage took place on a Sunday afternoon, priority was given to residence halls rather than administrative or classroom buildings.
Kempf did not say exactly which buildings were affected but confirmed that the Main Building did lose power as part of the outage.
"This type of outage is the most common to occur," Kempf said. "This happens when a lightning strike hits an overhead transmission line.
Typically the lightning strike is cleared in an instant, resulting in outages that are short -15 minutes or so - based on the time it takes to resynchronize with AEP, and then everyone is back up and running."
Kempf said Notre Dame has a highly reliable electric system. Outages like the one on Sunday are the uncontrollable result of Mother Nature, Kempf said.
A similar outage occurred on March 30 during a thunderstorm. Kempf said there have been slightly more instances of power loss in the last year than in previous years.
"It's not up to me how many outages there are. It's up to the weather and the random strikes of lightning. If you could tell us how to stop lightning, we'd fix it."
