Probably burning plastic of the copper cables ...
15 April 2011 Last updated at 07:36
M1 in London closed by scrapyard fire
The M1 in north London has been shut following a fire at a scrapyard.
The road was shut between junction 1 at Brent Cross and junction 4 at
Elstree at about 0430 BST and is expected to remain closed for several
hours.
About 40 firefighters have been tackling the blaze close to Ellesmere
Avenue in Mill Hill which is thought to involve several gas cylinders.
A number of nearby homes have been evacuated as a precaution and train
services have been disrupted.
Services on East Midlands trains between St Pancras and Sheffield have
been reduced to three an hour.
There are also delays and cancellations on Southeastern and First
Capital Connect services.
http://www.bbc.co.uk/news/uk-england-london-13090742