prompted an evacuation of the campus and injured at least one person, according to authorities.

A power outage was reported earlier in the evening and classes were canceled and students were told to suspend lab activity and leave the academic buildings, campus emergency officials said.

Shortly after, authorities reported an apparent ammonia leak in a room at Latimer Hall.

Then shortly before 7 p.m., an explosion was reported near Sather Tower, Berkeley acting fire Chief Gil Dong said.

At least one injured person was taken by ambulance to an area hospital; "a few others" suffered minor injuries and were evaluated by emergency personnel on campus.

Fire crews were also trying to free 20 people trapped in dormitory elevators on the west side of campus due to the power disruptions.

Vandals stealing copper grounding wire from an underground vault may have been to blame for causing the blast –- but officials said the cause of the other incidents, and whether any or all of them were related -- had not yet been determined.

This is a developing news story...