The most fortified residence on Earth, brought to a sudden, tense lockdown… by a curious toddler. This pint-sized infiltrator, with the stealth of a seasoned operative (or just a kid chasing a squirrel), squeezed through the wrought-iron fence bars. Secret Service agents swarmed, only to find the "breach" was barely knee-high and resulted in a "timeout" for the tiny trespasser.