The University of California at Berkeley campus was evacuated on Monday night following a power outage and subsequent explosion, Fox News reported.
The blast happened near Sather Tower around 7 p.m. One person was hospitalized and there were no reported deaths.
"The explosion was about two stories high and as wide as a two-lane street," said UC Berkeley spokesman Dan Mogulof. "We're very fortunate there were no serious injuries."
Students and faculty were immediately evacuated following the explosion, shortly before officials began investigating the cause of the power outage.
Mogulof said first responders saved about 20 people that were stuck in elevators across campus due to the outage, which occurred around 4:30 p.m., forcing administrators to cancel classes and all lab activities, Mogulof said.
Thirty minutes later, an ammonia leak was discovered in Latimer Hall but was quickly contained by authorities.
Sophomore Jay Reddy recalled the incident and said everyone was able to evacuate.
"The lights just went out," Reddy said. "People were a little bit confused, people were wandering around, trying to find their way out. The emergency lighting came on, and there was limited lighting in the stairwell, but people were able to get out."
It was two hours later that the explosion occurred in an electrical vault near California Hall as workers tried to get the power back on campus, according to Berkeley Fire Chief Gil Dong.
Officials believe the explosion may have been caused by an attempted underground copper theft, Mogulof said.
"The damage that could be seen and assessed was repaired over the weekend, but it now appears that the damage caused by the unknown vandals may have been far more extensive and may have been the cause of what happened," he said.
However, the causes of the other incidents have not been officially determined.
It is unknown when classes will resume.
"I have midterms tomorrow as do a bunch of other students on campus. A lot of students don't have power to study or get their laptops on or anything like that," said freshman Kelsie Carlson.
