The closest footage we have gotten so far of the moments leading up to this morning’s explosion at the Iranian port of Bandar Abbas. Orange smoke, likely nitrogen dioxide, being produced by a fire interacting with a still unknown chemical can be seen right before the explosion occurs; chemical compounds that would produce such smoke as well as the blast include ammonium nitrate, nitrogen tetroxide and nitric acid, all of which are likely to have been stored at Bandar Abbas.