EXCHANGE, Pa./WASHINGTON (Reuters) - A high-tech U.S. military blimp designed to detect a missile attack came loose on Wednesday and wreaked havoc as it floated from Maryland into Pennsylvania while dragging more than a mile of cable and knocking out power to thousands.

EXCHANGE, Pa./WASHINGTON (Reuters) - A high-tech U.S. military blimp designed to detect a missile attack came loose on Wednesday and wreaked havoc as it floated from Maryland into Pennsylvania while dragging more than a mile of cable and knocking out power to thousands.