I can't find the weight of that bridge directly, nor how they arrived at the value estimate, but if I'm reading it correctly, this (http://www.steelonthenet.com/commodity_prices.html) seems to say steel scrap was going for $428/ton in October 2011, so from the "estimated $100000" we can guess that it was about 234 tons of steel.
It actually sounds relatively low risk ("What are you doing!? Moving the bridge like this here paperwork says. We never approved that! Oh must have been a mixup..")
British newspapers tend to convert everything to pounds without citing the original figure. I find it really annoying since I can never remember the going exchange rate for GBP.
I can't find the weight of that bridge directly, nor how they arrived at the value estimate, but if I'm reading it correctly, this (http://www.steelonthenet.com/commodity_prices.html) seems to say steel scrap was going for $428/ton in October 2011, so from the "estimated $100000" we can guess that it was about 234 tons of steel.