Complex sentence: Jonathan had died on December 21,1988 at the age of 33, one of 270 killed in the terrorist bombing of Pan Am Flight 103 by Abdelbaset al-Megrahi over Lockerbie, Scotland.
Split into simpler sentences: Jonathan had died on December 21,1988 at the age of 33. He was one of the 270 people to die in the terrorist bombing of Pan Am Flight 103 by Abdelbaset al-Megrahi over Lockerbie, Scotland.