are equally concerned that isis is using social media, including facebook, you tube and twitter in a way that no terrorism organization has before giving them direct access to the u.s. there have been 250 on-line publications from isis since last month. al qaeda is active on-line too. as a result, authorities believe there are hundreds of radicals inspired on-line who could attack here at home on short notice. pierre thomas, abc news, washington. a twin-engine propeller plane crashed near miami killing all four people on board. the pilot tried to return to miami executive airport. instead it clipped a power line and burst in to flames. federal aviation administration officials say the plane was headed to turks and caicos. thousands turned out for a vigil at the university of north carolina in chapel hill for three students found shot to death. police are trying to determine whether hate played any role in the killing of three muslims.