60+ fires from a gas pipeline

[Autocon]

There are news reports about 60+ plus fires across America caused from a leak in a high pressure gas line. I dont quite understand how it works, the gas pushes out of the line into the home and kablewy?

[Thurmus]

Apparently a lot of the pipes in the area are cast iron and leaky. They had just finished some pipe works in the area and it is believed they over pressurised the pipes after the works.

This caused pockets of gas to form around the leaks which were set off by electrical sparks or pilot lights.