I recently read “The Lost Tub Saga” here and remembered the local saga.

I worked 15 years ago in an organization called The Heat Network. To provide the city and the area with hot water and heat.
We sent somehow a network brigade, which serves the pipeline network, to make a stitch in the current pipeline, i.e. to weld a piece of the pipe with a drive at the end to the pipe where hot water is already going, in order to connect the newly built house to hot water. And to do this action was in the area of the old housing fund built immediately after the war. The streets there, surprisingly, are very wide, and the houses are completely two-storey and very old, if it were not for the captive Germans, who built these houses in 1946, these houses would have long since collapsed. And it would be nothing, but there was no communication plan naturally. It was said that you will cover the water in the well and continue on the pipe. The water was blocked, but the pipe was not a task, they cannot find it. We made a few shurfs and found the pipe. Next is simpler. They picked up the welding generator, dragged the welder into the hole.
The welder begins to cut the pipe and here as a pillar of flame.
Everyone, except the worker. The pipeline was found, only the gas pipeline. Contacted by radio with the Gorgaz Emergency Service. There they were also scared at first, but then looked at their schemes, asked a few clarification questions and comforted. “Don’t worry, guys, this is a low-pressure pipe, in which gas goes to consumers, i.e. to the plates that are in the kitchens. So if you cut the pipe 5 meters away, then the problem is that there is a high-pressure pipeline.” “What to do? With the pipe?” asks the welder from the “Heatnet”. “Hey, take it and cook it!” The main thing is not to be afraid!They answer from Gorgaz. Hearing these words, the welder was quite daring and asked, "Maybe you know where our hot water pipe lies?"The gas drivers laughed, looked at their scheme, well, and co-oriented the welder. They are strict. When the gas was placed, all communications were applied.
P.S And the pipe welder boiled and made the necessary slice as well.