State police say two federal agents searching for a missing person exchanged gunfire with someone in a cabin on northern Michigan’s Drummond Island yesterday.     Hours later, state police found the person dead inside the cabin. State police say the cause was not immediately known.     The incident began around 2:30 a.m. when agents from U.S. Border Patrol discovered footprints and tracked them to a cabin. They were shot at and took cover while returning gunfire.

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