Within hours??????

Help I am looking in to some language for a friend who is not English and she thought I could help her but I can't


Within hours, local streets were reduced to chaos.

Within = preposition
hours = a noun as it is a unit of time
local   = is an adjective, deiscribing the streets
were  = I am not sure on this is a past simple tense of be.
reduced = verb, as it is an action
to = preposition
chaos = is a noun (resulting action)

Is this correct? I am not sure about within, reduced or chaos, any input would be great. Also were, but I am 90% on that.

Within hours, local streets were reduced to chaos.

A similar meaning (in active voice):

Before long, local streets became chaotic.

Within hours, local streets were reduced to chaos.

There are many cases in which an argument can be made for either the adjective or the passive verb.  I like to consider whether the inclusion of the agent seems reasonable; if it does, I plump for the passive:

Local streets were reduced to chaos (by the crowds).-- the agent seems grammatically/semantically appropriate, therefore a passive formation.
Mr Jones is now retired (by his company). -- the agent seems inappropriate, therefore an adjective.


Another guideline is whether the -ed word can serve as an attributive:

Mr Jones is a retired salaryman.-- OK as an adjective.
They were reduced local streets. -- NG; not an adjective.