is environment in MGS4 destrutible?

my question is do the environment in MGS4 are destructible ? also, does the battlefield occur streaming in real time? or just loading level by level?

i watched the gametrailer version of the latest video , its seem the environment are static after explosion.

if someone have any reliable info about MGS4 environment and real time battlefield then please post it.

i watched the trailer again and it seem some environment are indestructible.

anyway another question everyone forgot to answer is the battlefield occur in real time or its stop loading next level/area and loading like all of today games?