People forget that natural gas lines into a building are usually under fairly high pressure and if there is a leak and a nearby spark, the resulting explosion is like that of a fuel-air explosive bomb, which can literally bring down older structures. I'm surprised there hasn't been more of the explosions at older buildings in the northeastern USA.
Actually, the lines in a building aren't under much pressure at all. 1/4 psi above atmospheric is common, for the gas piping within a building.
But a leak and a spark can still be really, really ugly.
Not that I am an expert on the subject but perhaps we should give our gas companies and appliance manufacturer's some credit for designing equipment that basically works?
Also, the people that install them?
Not trying to start an argument here. Just pointing out that we do things pretty well in the USA.
God help the people in that building.
A lot of buildings in the northeastern USA are heated with heating oil, not natural gas.