Before 4ZZ could start broadcasting in 1975, a transmitter was ordered from the U.S. But after it was lost on the dock in New York, 4ZZ's chief engineer at the time Ross Dannecker built the station's first transmitter.
Twenty one Coptic Christians killed by IS
Egypt's National Defense Council met in an emergency session following the release of the violent footage, which shows the group dressed in orange overalls being forced to the ground and decapitated.
IS have claimed to have carried out several attacks in Libya; but several armed groups are operating in the country which effectively has no government, making it unclear how much power IS wields in the North African nation.
Libya currently has two rival governments based in Tripoli and Tobruk whilst the eastern city of Benghazi, headquarters of the 2011 Arab Spring revolution, is now held by Islamist fighters linked to al-Qaeda.
Egypt has declared seven days of national mourning.