Question: How many terrorists were on the second plane to hit the World Trade Center?
Sentence (from "United Airlines Flight 175"): On September 11, 2001, the Boeing 767-200 operating the route was hijacked by five al-Qaeda terrorists and flown into the South Tower of the World Trade Center in New York City, killing all 65 people aboard and an unconfirmed number in the building's impact zone.
Relevant evidence: Yes