Complex sentence: The "Sewol" capsized in the Maenggol Channel carrying 476 people, mostly secondary students from Danwon High School; 172 passengers and crew survived, while 304 drowned or are still missing.
Split into simpler sentences: The "Sewol" capsized in the Maenggol Channel carrying 476 people, mostly secondary students from Danwon High School. Of that, 172 passengers and crew survived, while 304 were drowned or still missing.