[Vinnie]

noticed what they thought was smoke billowing inside the car.

Apparently the perps left one of the propane cylinders cracked open. Probably to ensure ignition.

Propane has the same refrigerating properties as 'Freon' R-12 and would get very cold as the liquid boiled off.

In the humid London air clouds of vapor would have ensued.

This could have resulted in a hyperbaric type bomb, crushing anything near it.

[jimbo123]

http://news.sky.com/skynews/article/0,,70131-1272910,00.html

Sources say police believe the bomb was to be detonated by a mobile phone trigger.