The president, vice-president and other senior government officials fly in and out of Joint Base Andrews. The confusion was heightened by a planned active shooter drill at Joint Base Andrews that had not yet begun and was planned for later in the morning. ET after an active shooter was reported. Vice-President Joe Biden was scheduled to leave from Andrews on Thursday morning, but his trip was delayed by the lockdown. Officials said in a Facebook post Thursday that there was no shooter and no threat to the base or workers there.

Source: CBC News June 30, 2016 14:07 UTC