UPDATE: Electricity restored after UC Berkeley power outage

Update, Thursday, May 23, 4:20 p.m. UC Berkeley said Wednesday's large-scale power outage was caused by a "spontaneous equipment failure."

Cal spokesman Dan Mogulof said the university is still working to learn more.

"We will be bringing in a third party for a full forensic investigation to determine the exact cause of the equipment failure," he said.

Original story: A power outage hit UC Berkeley on Wednesday evening, knocking out electricity to dozens of buildings on and near campus.

As of 10 p.m., there were 47 UC Berkeley buildings without power, the university announced.

"High-voltage electricians are on-site and have identified the source of the outage," campus officials said in the 10 p.m. statement. "It is estimated that it will take 6-8 hours to fully restore power."

In a subsequent update, on Thursday at 12:15 a.m., the university said all power had been restored.

Cal has not said what caused the outage and PG&E's outage map said none of its customers in Berkeley were without power as of about 10:30 p.m.

One Cal community member writing on Reddit said "a small transformer explosion" at a Lawrence Berkeley National Laboratory (LBL) power station may have been to blame.

"It sounds like it was the cause," the Reddit user wrote. "They had an electrician inspecting. No fires or anything, just a burnt up part."

"It's the cause," another Reddit user replied. "That substation is actually two substations, one that feeds LBL, and one for the Berkeley campus, and the feed that blew was the Berkeley campus feed."

One Reddit user described being in Cory Hall, on the northeast side of campus, at about 6:30 p.m. Wednesday when the power went down, taking elevators and labs out of service.

"This is a bad one," a fourth Reddit poster wrote. "It's been going for so long. Kind of goes to show how vulnerable the university is if there's a disaster. Our infrastructure isn't nearly robust enough."

A UC Berkeley spokesman said more information would be available Thursday.

Even once power is restored, UC Berkeley said in the 10 p.m. statement, "confirming that all building systems are fully functional will take some time. This work may continue through Thursday morning."

Cal activated an Emergency Operations Center to tackle the widespread outage, which it initially announced to the public by text just before 7:30 p.m.

"Please use caution when walking in dark areas," the university said. "Students and staff in residence halls have been contacted directly with additional instructions."

Cal's spring semester ended May 10 and its first summer session began Monday, according to the academic calendar.

UC Berkeley said it will update its main announcement as more information becomes available.

UC Berkeley buildings without power as of 10 p.m.

• 2251 College
• 2350 Bowditch
• 2547 Channing
• 2610 Channing (RSSP)
• 2850 Telegraph
• Anna Head A
• Anna Head E
• Anthropology
• Berkeley Law
• Blum
• Botanical Garden
• Calvin
• Campbell
• Cory
• Davis
• Etcheverry
• Evans
• Faculty Club
• Gilman
• Greek Theater
• Haas Clubhouse
• Haas Pavilion
• Haas-Cheit
• Haas-Chou
• Haas-Faculty
• Haas-Student
• Hargrove Music Library
• Haviland
• Hearst Field Annex
• Hearst Gym
• Hearst Mining
• Hertz
• Hesse
• International House
• Jacobs
• Lewis
• McCone
• McLaughlin
• Memorial Stadium
• Minor
• Morrison
• North Gate
• O'Brien
• Physics
• Residence Hall: 2535 Channing (Channing Bowditch)
• Residence Hall: Unit 1-Cheney
• Residence Hall: Unit 1-Deutsch
• Residence Hall: Unit 1-Freeborn
• Residence Hall: Unit 1-Putnam
• Residence Hall: Unit 2-Central
• Residence Hall: Unit 2-Cunningham
• Residence Hall: Unit 2-Davidson
• Residence Hall: Unit 2-Ehrman
• Residence Hall: Unit 2-Griffiths
• Residence Hall: Unit 2-Towle
• Residence Hall: Unit 2-Wada
• Residence Hall: Unit 4-Hillside 4
• Residence Hall: Unit 4-Hillside 5
• Residence Hall: Unit 4-Hillside 6
• Residence Hall: Unit 4-Hillside 7
• Residence Hall: Unit 4-Hillside 8
• Residence Hall: Unit 4-Hillside 9
• Residence Hall: Unit 4-LaLoma 1
• Residence Hall: Unit 4-LaLoma 2
• Residence Hall: Unit 4-LaLoma 3
• Residence Hall: Unit 4-Stern
• Rugby
• Senior
• Simpson Center
• Soda
• Strawberry Canyon
• Women’s Faculty Club
• Wurster