Complex sentence: On 30 December 1993, Joe and Mark argue over a vacuum cleaner that needs returning so Mark goes to the Whiteley Farm when a large section of an Eastern European Airjet comes down, knocking down a wall which falls on Mark, killng him.
Split into simpler sentences: On 30 December 1993, Joe argues Mark over a vacuum cleaner that needs returning. As a consequence, Mark goes to the Whiteley Farm when a large section of an Eastern European Airjet comes down, knocking a wall which falls on Mark, killng him.