What is a sonic boom and why did D.C. residents hear it Sunday?
NORAD scrambled F-16 fighter jets to respond to an unresponsive plane. NBC News Pentagon Correspondent Courtney Kube explains what caused the sonic boom heard over D.C.
NORAD scrambled F-16 fighter jets to respond to an unresponsive plane. NBC News Pentagon Correspondent Courtney Kube explains what caused the sonic boom heard over D.C.