How big was the blast? One report estimated that a third of the city's population is now homeless due to damages to buildings from the blast.
In comparison, if you recall the Oklahoma City bombing, they used a truck bomb filled with 5,000 pounds of ammonium nitrate, plus other elements to totally destroy a federal building.
This article explains a bit more about the characteristics of the chemical, What is ammonium nitrate, the chemical that exploded in Beirut?
Really, what the story of the explosion is about is the lack of action by multiple levels of government, including the port to remove the hazard from the port area -- that was clearly known to have existed.
This article explains how the ammonium nitrate came to be stored at the port, Beirut explosion: How ship's deadly cargo ended up at port.
In the end, no one wanted to take responsibility for moving the fertilizer out of the port, because it would cost money and who had the authority, and on and on.
I am sure many a person has said to themselves before the explosion, "Nothing has ever happened before."