Reason 4389 Why LA Needs A Museum About Itself!

It an article about preserving the historic concrete bridges crossing the the Los Angeles River in today's LA Times is the below quote:

The bridges in question, most of which were constructed between 1910 and 1930, were part of a campaign to deal with a river that was prone to flooding and had destroyed many of the metal truss bridges built in the 1840s.

The idea that the LA river had even one - much less ... many... metal truss bridges in the 1840's... is bizarre enough... but when it appears the article is suggesting the bridges built after 1910 were to replace some of those recently destroyed 1840's bridges, it verges into science-fiction.