The Cuyahoga river, in Cleveland, was so polluted that it caught fire repeatedly. There were notable fires in 1868, 1883, 1887, 1912, 1922, 1936, 1941, 1948, 1952 and 1969. In 1968, the city was making efforts to clean the river, and the 1969 fire was portrayed as “a turning point” to help push people to care for the environment. Today, the river is a site of recreation. (http://bit.ly/2YkK7rW)