For the norm........ Natural gas will burn and not blow. A 8" main was hit in our town when they were building a new jail. Had a flame about 20' in the air. They brought in a welder and a backhoe dug around it and then welded it. Flame kept getting smaller and then boom it was all out. I had much rather dig around natural gas than propane. Just be careful around all of it. I have been doing this crap full time since 1964.
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