preposition description with nouns

Between the barriers a lone car sits, enclosed by the glum fog, waiting patiently for the frozen light to turn green. Beneath the decaying bridge a cold grey river surrounds the remenants of the once inhabited city. Above, lost in the clouds of the explosion, a single pig flies upon the building searching for any sign of life. On the bridge vigilant soldiers await the unknown, prepared for battle. Within the caged building dust coats the lifeless factory, untouched since the war.

Respond now!