Complex sentence: The ship continued to deteriorate after the clean-up, She already had split into about four pieces when winter storms in February 2016 pushed the wreck onto its starboard side and broke its rear half open.
Split into simpler sentences: The ship continued to deteriorate after the clean-up. While she had over the decades been broken into into four roughly segmented pieces, winter storms in February 2016 pushed the wreck onto its starboard side and broke its rear half open.