Complex sentence: There were a total of 515 personnel on board the Liebe Delta at the beginning of the dive, of whom a total of 486 were successfully evacuated, meaning that a total of 29 people were killed in the sabotaged dive.
Split into simpler sentences: There were a total of 515 personnel on board the Liebe Delta at the beginning of the dive. Meaning that a total of 29 people were killed in the sabotaged dive.