I was at Fort Sill, Okla., for basic and was training for a tear gas attack. We were told to enter in line with masks on towards a 55 gallon drum, then were told to take masks off. Drill Sgt. Knox lit a canister of gas and put it in the drum, then all of a sudden he was in our faces welling out orders. Then all hell broke out among all of us, running for the door, crying and puking. Never again will I take my mask off.