The White House was put on lockdown for more than two hours on Monday morning after a 'quadcopter' drone was discovered on the lawn.
A U.S. Secret Service officer on duty saw and heard the two-foot-wide commercial drone fly at a low altitude into the heavily guarded complex and crash on the southeast side at 3.08am, the agency said.
'An investigation is underway to determine the origin of this commercially available device, motive, and to identify suspects,' a Secret Service spokeswoman said in a statement.