More than 600 people are without power in the Lake Merced area of San Francisco – including portions of San Francisco State University.

The outage occurred around 11 a.m. Monday, according to PG&E spokeswoman Fiona Chan.

The cause is unknown, but initially more than 2,400 people were affected. That number dropped to 624 still without power around noon.

Chan said crews are on scene to restore power as quickly as possible. There is no estimated time power will be restored.

The university was among the affected customers and students needed to be rescued from elevators. The school announced classes will be cancelled for the remainder of the day. However the downtown campus is not affected and classes there will be held as usual.

Customers in surrounding areas and parts of Daly City were also affected.

akoskey@sfexaminer.com