The Death and Life of the Great Lakes by Dan Egan:
Cleveland was not the only Great Lakes city to make an industrial mess of a river. Similar fires blazed on tributaries from Chicago to Detroit to Buffalo, beginning in the late 19th century and stretching deep into the 20th century. The chemical dumping that caused these fires occurred with impunity because the federal water pollution laws that existed up into the 1960s were toothless to stop industries and cities from treating rivers as liquid landfills; civil and criminal penalties for polluters were basically nonexistent.
It was into this regulatory abyss that a spark dropped from a train passing over the Cuyahoga River on the morning of June 22, 1969. The flames were put out in a matter of minutes and merited only a small news item on page C-11 of the Plain Dealer. But then, like drifting embers, word of the fire landed in newspapers across the country, and a national outrage flared.