Natural gas pipelines can, and do, explode. This is a given when a pipeline is ruptured by a piece of equipment and there is an ignition source nearby. However, it also happens when the pipe fails, usually due to corrosion at a weld. The photograph above shows the fire following an explosion on a TransCanada Pipeline natural gas line in Wyoming in July 2011. This was a 30-inch diameter pipe, newly in service, that suffered a 60-foot long explosive rupture. Read about quality concerns raised before and after the explosion here, here, and here. One critic (a former employee) has accused TransCanada Pipelines of a "culture of non-compliance" with regard to safe construction practices.
Read what happens when that culture is abetted by the National Energy Board, the natural gas pipeline regulator in Canada.
Each of the photographs below shows an explosion site on other segments of natural gas pipelines operated by TransCanada. Click on the link below each for more information. Note the proximity of buildings in two of the photographs.