says they were purging gas lines...... sounds like somebody let the gas accumulate indoors....
The explosion that killed five and hospitalized 27 people occurred immediately after the purging, or cleaning, of the underground natural gas pipeline that runs about 800 to 1,000 feet through the plant.
this photo looks like a building that might house indoor boilers.. with walls blown out.
sure will be interesting to hear how this happened. These big disasters seldom have just one obvious cause they're result of a lot of little minor wrongs stacked up then somebody tips the first domino.
Cogito ergo doleo.