FILE - In this March 24, 1994, a fireball, at rises from a gas pipeline explosion in Edison, N.J. It took two-and-a-half hours to shut the manual valves on the spewing 36-inch pipeline. The blast caused $25 million in property damage and two serious injuries. An Associated Press investigation found that the utility, Pacific Gas & Electric Co., agreed as far back as 1997 that remotely operated valves did a better job of protecting public safety than manual ones. But it opted against using them widely across its network of high-pressure transmission lines, saying they weren't necessary or required. (AP Photo/Val Mazzucca)