Could I take your name and number, please? erythromycin mg acne The Tier II system came under scrutiny after the explosion of a fertilizer plant in West, Texas, in April. Minutes after firefighters arrived, 40 tons of ammonium nitrate exploded, killing 11 first responders. Though federal officials say a Tier II report was on file at the fire department, surviving firefighters told Reuters they had never seen a report detailing what chemicals were stored at the factory. Had they known, they may well have stayed outside the blast zone.