In 1947, one of the largest industrial disasters, ever, occurred in Texas City, Texas, killing over 500 people and destroying over a 1000 homes, and came about, in great part, through the ignorance of U.S. Coast Guard personnel, on the scene. The Coast Guard ordered the closing of the hatches of a vessel whose cargo of ammonium nitrate was on fire The Coast Guard official thought that by closing the hatches, the fire could be smothered, ignorant of the fact that ammonium nitrate is an oxidizing agent. In effect, the vessel became a giant bomb when the gases being produced, in the fire, became confined.
For many years, as a Maritime Consultant, the transport of explosives, by sea, was an area in which I specialized. Shipping was done in small vessels, usually under 1000 tons in deadweight capacity, whose holds could be flooded, by sea water, in the event of fire. They operated between small ports where populations were less dense, but where officials could rigorously observe procedures. There was, to my knowledge, no serious accident involving commercial explosives, shipping in conventional vessels. Coast Guard officials, however, became more convinced that it was safer to ship explosives in containers than to follow the disciplines in shipping by sea, in conventional vessels. I, on the other hand, considered that each container would be a potential 20 ton bomb.
In the recent disaster, in Tianjin, China, a port through which China exports a large quantity of commercial explosives, the tragedy started in a container yard, where containers were awaiting shipment. All that was needed was for a single container to explode, to set off a catastrophe. To accurately gauge the potential damage, consider that the largest single bombs, containing non-nuclear explosives, were, so-called, 15 ton "Daisy Cutters" which devastated large areas when dropped by U.S. Forces in Viet Nam.