While this is true, and I agree it's also a tragedy, I don't think that bringing this up in this type of debate is going to have the effect that you want it to. The immediate assumption is going to be that you're trying to deflect -- typical rearguard action along the lines of "how can you complain about this while that is happening" or "this happes so that can't be all that unacceptable". Both of these strategies are typically used by people who just don't want to change this and can't or won't come up with any actual valid arguments. If this is not your intent, then you may want to rejigger your statements a little.
my statement was in reply to bones, who mentioned that 10,000 deaths isn't enough to get people riled up about changing gun laws. I wasn't using it as a defense, I was merely pointing out another killer which gets no real publicity. MADD does great work, but it's just doesn't carry the gravitas in which it should. I only meant it response saying how fucked up our American society is, in that we don't really get upset about any of the killers in our nation like guns or alcohol, but we sure enough attack marijuana like it's the next hitler.
Sorry if it came across as a defense or if it wasn't clear. I'm a damn engineer...i'm not good at this essay type writing/defending position stuff