What is the nature of the incident with Casualties of 3 wia, and Circumstances of ied?
CREATE TABLE "2004" (
  "date" text,
  "location" text,
  "nature_of_incident" text,
  "circumstances" text,
  "casualties" text
);
SELECT "nature_of_incident" FROM "2004" WHERE "casualties"='3 wia' AND "circumstances"='ied';