Watch out for: bombs and bombers.
D005107:Explosions / Q000517:prevention & control*; D006761:Hospitals; D006801:Humans; D010820:Physicians; D010934:Planning Techniques; D011177:Postal Service; D012637:Security Measures / Q000458:organization & administration*; D014481:United States; D014754:Violence / Q000517:prevention & control*