I can only speculate as to how a Jeep fire engine from Newfields, MO, ended up in the UK.*
Having done a bit of digging around, it appears it was at a show in Kettering, Northamptonshire, organised by the
Military Vehicle Trust.
There's also a few stills on the LiveLeak page.
* I'm making a huge assumption that it is the genuine article and not a vehicle restored in the guise of a fire truck according to the owner's whim.