(Decatur, IL) -- A pair of 18-year-olds with a BB gun prompted a 90-minute lockdown of Our Lady of Lourdes School Thursday. A teacher and two students spotted the men outside of the school with what they believed to be a firearm and called police. Officers quickly caught up with the duo and arrested them on preliminary charges of disorderly conduct. Administrators say the 238 students attending the school flawlessly responded to the lockdown order. They recently conducted a lockdown drill and knew exactly how to respond.