NEWORLEANS- Louisiana's integrated system of underground oil and gas pipelines crisscrosses every major highway, railroad and navigable waterway in the state, according to the Department of Natural Resources. Some industry watchdogs say recent explosions and fires raise concerns about efforts to protect the system.
In September 2010, when a 30-inch underground natural gas line ruptured in San Bruno California, residents heard such a loud boom they thought a plane had crashed. The rupture was followed by a horrific blaze right in the middle of a densely-populated neighborhood.
'Eight people lost their lives, 38 homes were destroyed and another 60 homes were damaged,' said Connie Jackson, city manager of San Bruno. She was in New Orleans last week for a conference on pipeline safety.
Then, this past June, right here in Louisiana, an underground gas line exploded in Washington Parish. Residents reported hearing the explosion, and seeing the huge fireball.
But people in Louisiana were lucky. There were no injuries or major damage. The 30-inch underground gas line that exploded in flames in Washington Parish was in a rural area, scorching the earth, clearing away trees and brush for 300 feet around. 55 families within a mile only had to be evacuated.
San Bruno is still trying to recover from the tragic loss of life and property there.
'An entire neighborhood was, and continues to be, traumatized by the experience,' Jackson said.
The tragedy has transformed her into an activist for pipeline safety.
'Unfortunately what we learned was that the utility did not uphold its responsibility to maintain and operate the pipeline in a safe manner,' she said.
A map of the nation's regulated underground pipelines shows Louisiana should also be concerned.
'I think there's a need to be concerned. There's been a number of high profile incidents in the last few years,' said Carl Weimer, executive director of the Pipeline Safety Trust.
Just last week, an oil pipeline explosion in China killed more than 50 people. Just last month, people in Oklahoma escaped injury when an underground pipeline exploded in a rural area. Some say the sheer amount of regulated underground oil and gas pipelines in Louisiana - close to 50,000 miles, according to the state - increases our vulnerability.
'It's definitely ground zero for pipelines, you know, Louisiana, Texas. That's where all the oil and natural gas is being pumped out of into refineries around the country,' said Darryl Malek-Wiley, of the Sierra Club of Louisiana.
What's more, the condition of some above ground pipelines raises questions about the condition of those you can't see.
And some at the pipeline safety conference that brought Connie Jackson to New Orleans question whether regulators across the country are doing enough to protect the public.
'I have to say that I do not think so,' Jackson said.
It turns out a lot of pipelines around drill pads are not regulated at all.
'And the state regulators and the Pipeline Safety Trust and a lot of advocacy groups are really pushing for the need for regulating them. Louisiana's full of them,' Weimer said.
He added that safety starts with knowing where the underground pipelines are located. People in San Bruno had no idea the pipeline was there, and it was close to an hour before they realized they were dealing with a ruptured pipeline.
The Association of Oil Pipelines, representing lines that carry liquid petroleum, says its members spent $1.6 billion last year evaluating, maintaining and inspecting pipelines. It also says incidents are down 62 percent in ten years.
The Interstate Natural Gas Association of America says it has worked to enhance safety measures since the San Bruno incident and, like the Oil Pipeline Association, says it has a goal of zero incidents.