Complex sentence: When Perón returned to Argentina (June 20,1973), his plane has to be redirected to a military airport because of the armed fighting between peronist factions, known as the Ezeiza Massacre, that left 13 deaths.
Split into simpler sentences: When Perón returned to Argentina (June 20,1973), his plane had to be redirected to a military airport because of the armed fighting between peronist factions. This event, known as the Ezeiza Massacre, that left 13 deaths.