By: +David Herron; Date: April 27, 2017
These are examples of what really happened on the Thames when Winter conditions froze it solid. Thanks to climate change we probably won't see this for a few thousand years.
To learn more: https://en.wikipedia.org/wiki/River_Thames_frost_fairs We learn there this:
The frost fair of 1814 began on 1 February, and lasted four days. An elephant was led across the river below Blackfriars Bridge. A printer named George Davis published a 124-page book, Frostiana; or a History of the River Thames in a Frozen State. The entire book was type-set and printed in Davis's printing stall, which had been set up on the frozen Thames. This was the last frost fair. The climate was growing milder; old London Bridge was demolished in 1831 and replaced with a new bridge with wider arches, allowing the tide to flow more freely; and the river was embanked in stages during the 19th century, all of which made the river less likely to freeze.
Nothing about a giant fish under the ice eating people. Wikipedia obviously can't know everything.
The BBC printed an article in 2014: http://www.bbc.com/news/magazine-25862141 Imagine roasting a whole Ox, on the Thames, a process that took 24 hours, without falling through the ice.