On Tuesday, 2,750 tonnes of ammonium nitrate stored in a hangar at Beirut’s port caused a massive explosion, killing scores of people, injuring thousands, and destroying much of the city. Documents published online show senior Lebanese officials knew for more than six years that the ammonium nitrate was stored in Hangar 12 of Beirut’s port, and that they were well aware of the dangers it posed. Reports indicate that the cargo of ammonium nitrate arrived in Lebanon in September 2013 on board the Russian-owned cargo vessel, Rhosus. The vessel was forced to dock in Beirut due to technical problems at sea, but Lebanese officials prevented the vessel from sailing, and eventually it was abandoned by its owners and crew. The ship’s cargo was then offloaded and placed in Hangar 12. Over the years, customs officials have sent at least six letters to officials asking for guidance and warning that the material posed a danger. They proposed three options: Export the ammonium nitrate, hand it over to the Lebanese Army, or sell it to the privately-owned Lebanese Explosives Company. None of the letters received a response.