The expression '1 turn' seems a bit ambiguous.
My interpretation for this is that a creature dies only when its HP is 0 right after its attack. Is it OK to think so?
Then you don't need to worry about Spark; it will die normally since its HP is 0 after its attack, unless buffed somehow.
Or, if a creature's HP is reduced to 0 during its attack (because of Fire Shield, etc.), then does it remain alive for next turn?