Last week, an explosion in an underground power vault near the chancellor's office shook the University of California-Berkeley campus, triggering a power outage. The day after, school officials increased security around the power grid, but said they believed there was no danger of another blast.

According to a report from the Wall Street Journal, the underground explosion is believed to be connected to the theft of copper wiring. Thieves are believed to have accessed the wiring at a remote location on campus and tried to pull it out with some type of machine, a school official said.

School officials said 113 classes had been canceled Tuesday, and 11 buildings were still without power. But generators were being brought in to restore power to those buildings, while engineers continue to investigate that portion of the grid. The incident took place at 6:45 p.m. Monday night in an underground power vault on a central part of the campus...(Wall Street Journal)