Former Federal Energy Regulatory Commission chairman Jon Wellinghoff says he believes an April attack on Silicon Valley's phone lines and power grid was terrorism.  

News10 spoke Rich Lordan of the Electric Power Research Institute who backs up Wellinghoff's assertion on the attack.

"They knew what to cut in communications systems, they knew where to cut it. They knew what equipment to go after and they also knew how to get out of there before the police and fire came," Lordan said. 

As FERC Director, Wellinghoff said he reached his conclusion after consulting with Defense Department experts to review the attack that involved cutting AT&T fiber-optic lines to knock out phone and 911 service as well as opening fire on transformers at the substation with a high powered rifle from a long distance.