Bomb threat empties state power-grid offices - Published 12:00 am PDT Tuesday, April 17, 2007 Authorities on Monday were investigating two suspicious incidents involving the California Independent System Operator that led to the evacuation of employees from their offices, officials said. A suspect had been identified but had not yet been arrested, ISO spokeswoman Stephanie McCorkle said Monday night, adding she could not say whether the suspect is an ISO employee. Power to several ISO computer systems was interrupted late Sunday, McCorkle said, but it did not affect the state's power grid, and all systems were restored by 6 a.m....