Suggested reading: this chilling account of the Rancho Cordova, CA pipeline explosion, which occurred on Christmas Eve, 2008. It was a 2" pipeline. Following the 9:16 am report by a homeowner who smelled gas, PSE&G workers arrive on the scene to investigate. Various events occur, including the break down of a truck to transport needed equipment, and the failure to warn residents of a potential leak or evacuate. Eventually, workers locate the source of the leak, marked by dead grass in the front yard of one house.
(One of the standard ways pipelines are "inspected" is to walk the route looking for dead trees or grass. This is one of the inspection methods proposed for the Spectra pipeline, a project which will traverse many cemented, paved, and underwater areas.)
Turns out, this section of pipeline had previously been repaired. The later investigation will show that nonstandard replacement materials were used, causing the leak.
At 1:35pm, as a worker turns away from the front door of the house with dead grass, having just finished a conversation with the owner, the house explodes. The owner, a grandmother, dies from her injuries. Five others are also injured. Evacuation commences at 2pm.