TOPIC: Adjective ???

I have read a sentence:
Eighteen people are know dead and over 100 have been injured in Ambon....."
As far as I understand that the word "known" used here is adjective, and the word "dead"
here is also used as adjective.
That means two adjectives are used in sequence. Is my understanding corrected?

Actually, " known " is used here as a passive verb, not as an adjective. Think about what the sentence would look like when you put the actor in:
" Authorities know (that) 18 people are dead."
Compare that with this passive one:
" Eighteen people are known (to be) dead ( by authorities ).
As you know, we CAN use two or more adjectives in sequence ( e.g., the big red metalic building) but in the case of your example, we do not have two adjectives in sequence.