It is a horrendous tragedy. We are talking about, roughly, 3 kilotons of ammonia nitrate exploding and no, this is not an attack or terrorist act. Ammonia nitrate is extremely volatile and more than 3,000 tons of it has been stored at Beirut's port since 2014, when the vessel, owned by some Russian/Cyprus dude, while transporting this deadly cargo from Georgia to Africa broke down. It is not surprising knowing corruption in Lebanon that this cargo was stored without any regard to safety and special handling procedures. The luck simply ran out for Beirut which looks like a Hiroshima or Nagasaki now.
For conspiracy imbeciles who try to push some "nuclear explosion" BS--learn main destructive properties of nuclear explosions among which light flash is a main one. Nothing, including a brownish smoke--a first sigh of chemical explosion--points out to any nuclear blast. The world better get its act together and drop this "attack" BS (such as Trump already suggested) and start helping people of Beirut. Even Israel offered help immediately, first flight with Russian doctors has already landed in Beirut and first five IL-76s are already on tarmac in Russia ready to fly in field hospitals and supplies, the United States (despite Trump's snafu) already offered any help--the US Navy is there in the Med and it is at its best when providing massive humanitarian assistance. I am sure many other countries will respond with help. Beirut has only 1 month worth of food currently and hospitals are filled with wounded. It is a horrendous tragedy.
This will require an extraordinary international effort to help people of Lebanon.