Houston, Mar 11 (Reporter) Three people were killed after a medical helicopter crashed in Madison County in the southern U.S. state of Mississippi on Monday, killing all three people on board, local officials confirmed. The victims included the pilot and two hospital staff members, local media reported. The University of Mississippi Medical Center confirmed in a statement that no patients were on board at the time of the crash. Madison County Sheriff's Office said the helicopter went down in a heavily wooded area. Investigation is underway to determine the cause of the crash...////...