If it were a gas explosion, shouldn’t there be a fire?
Most of those shopping malls are made with metal studs, fiberglass insulation and drywall. Non of it is flammable. Fiberglass just melts.
Not sure about the supply of gas. Maybe a safety valve at some point in the system shut the supply off or the explosion somehow shut it off.
I imagine firemen or gas people shut it down manually asap.
the feed line would still be torching away.....
A small leak in a nonventilated area, the gas accumulates over time.
Also, the gas is lighter than air and rises, if the source of ignition is near the floor (burner on a water heater) and air gas mix is above the LEL (lower explosive limit)...
Not good.