Bridge On The River Kwai was a hit movie released in 1957. It won 7 Academy Awards. The World War 2 movie was about the constructing of a tall wooden bridge over that river. I saw the movie and read books about the “death railway”. If you think the Nazis were despicable because of their Holocaust, the Japanese were far worse as their focus of abuse and cruelty knew no bounds. Hundreds of thousands of prisoners died working as slaves for the Japanese military, and many of them, on the “death railway”. Anyway, the movie turns out to be fiction and has nothing to do with the real bridge. The book, from which the movie was based, was written by a Frenchman. Apparently the book was a way to show the authors displeasure of the pompous, elitist attitude and unwavering bent to follow rules, when common sense would have been a better option, by the British military officers.
The first bridge over the Kwai was a quickly built low level wooden service bridge. The primary bridge was actually a bridge from the island of Java in Indonesia. The spans were disassembled and shipped to the Kwai river near the city of Kanchanaburi, Thailand. POW slaves constructed the concrete supports while the spans were in route. When the arched spans arrived by barge, they were lifted into place and fit perfectly. The movie portrays the Japanese engineers as inept. 
Another thing, the movie has British soldiers whistling a merry tune as they march into the POW camp and, assumably, as they march off to work on the bridge as though they were happy elves. Most POW slaves were little more than skin covered bones, from starvation, and could hardly get to a job site.
Eventually the two arched center spans were bombed by U.S. aircraft. The Japanese built box beam spans to replace them. So Hollywood has always made entertainment, not documentaries.
