Most U.S. gaslines not inspected with latest technology

This week I read an article about gas line inspections. The main points of the article were:

• 2/3 of America's natural gas lines are susceptible to deadly faults because they can't use the industry's best technology for testing and cleaning
• Last week in San Bruno California a gas main exploded: at least 4 killed, dozens injured, many houses destroyed.
• it was made of steel which is regarded as a safety hazard because it is too rigid and easily corrodible
• robots called "smart pigs" clean pipe interiors, send data on flaws, and even fix leaks

Basically this article was about how a large amount of America's gas lines are in unsafe conditions. The "smart pigs" are unable to enter some pipes because they are too old and "twisty."

I feel very unsettled knowing about 2/3 of gas lines in America are in sketchy condition, and the majority of these are major lines. I really hope there is not a repeat of the incident in San Bruno, California, but if things aren't figured out and taken care of, it looks like that could be a definite possibility.