Miami Herald 
April 20, 2011
Several large military-style helicopters conducting a training drill caused a stir in downtown Miami Tuesday night.
At around 9:15 p.m., at least three large choppers landed in a parking lot of the Adrienne Arsht Center for the Performing Arts on Biscayne Boulevard and 14th Street. The choppers, which resemble Black Hawks, then flew over Brickell area. SWAT team members were also seen taking part in the exercise.
Some who witnessed and heard the powerful choppers sent out Tweets fearing a real event was unfolding.
Miami Police at the scene said it’s all part of a planned Homeland Security exercise that will go on until 11 p.m..