Complex sentence: The crewman manning the sonar notices a large, swift object coming into contact with the ship, and the ensuing crash causes the passengers to panic as one passenger runs into a bathroom, only to be pulled through the toilet.
Split into simpler sentences: The crewman manning the sonar notices a large, swift object approaching which then collides with the ship. The ensuing crash causes the passengers to panic as one passenger runs into a bathroom, only to be pulled through the toilet.