Complex sentence: In June 1942 four men were brought by submarine and landed on Long Island, planning to destroy such sites as the Curve, Hell Gate Bridge, Alcoa aluminum factories and locks on the Ohio River.
Split into simpler sentences: In June 1942 four men were brought by submarine and landed on Long Island. They planned to destroy such sites as the curve, the Hell Gate Bridge, Alcoa aluminum factories and the locks on the Ohio River.