My thermodynamics professor was there as a young scientist when this happened. From what he told us (probably in clear breach of the Official Secrets Act) this was a truly terrifying accident. The absence of temperature data meant that it was impossible to know how extensive the fire was or what remedies would work. Eventually, in desperation, water was used despite the clear hazard of creating a catastrophic Hydrogen/Oxygen explosion. My professor recalled being sent up these towers to monitor any radiation release, perhaps an early example of "this is a job for the intern".
This accident, along with quite a few others, is covered in the excellent book: <i>Atomic Accidents: A History of Nuclear Meltdowns and Disasters: From the Ozark Mountains to Fukushima</i> by James Mahaffey:<p><a href="http://www.amazon.com/Atomic-Accidents-Meltdowns-Disasters-Mountains/dp/1605984922/ref=sr_1_1?ie=UTF8&qid=1415135359&sr=8-1&keywords=atomic+accidents+a+history" rel="nofollow">http://www.amazon.com/Atomic-Accidents-Meltdowns-Disasters-M...</a><p>Edit: The book is no way anti-nuclear and actually starts with a description of a horrific accident at a hydro-electric plant.
I think Cockcroft is a small hero in this story. He expended significant political capital to push through a very unpopular idea because he could see the importance at a time when absolute safety was not the first concern. Brave.