6 small blasts preceded large Beirut explosion: Israeli seismologist

The large Beirut explosion on August 4 was preceded by six small blasts spaced at 11-second intervals, the last of which was a combustion of fireworks that apparently set off a warehouse full of ammonium nitrate, an Israeli seismologist said. The first five blasts may have taken place underground and gone unheard by Beirut witnesses, Boaz Hayoun further told Reuters.