From the BBC report:
// Actually we were shocked because usually when it happens, just one area will experience those happenings after an explosion, but this time it was all of Beirut, even areas outside of Beirut. //
Usually ?
They knew it was unsafe for six years but now they will look for "those responsible."
The BBC Link you posted in OP suggests "President Michel Aoun tweeted it was "unacceptable" that 2,750 tonnes of ammonium nitrate was stored unsafely."