Input (grade 13): The flight was hijacked by five al-Qaeda-associated Islamist terrorists on the morning of September 11, 2001, and flown into the South Tower of the World Trade Center in New York City as part of the September 11 attacks.
Output (grade 11): United Airlines Flight 175 was the second hijacked airplane of the September 11, 2001 attacks that crashed into the South Tower of the World Trade Center.