Part 6/8:
Both Betty Angu and Amy Sweeney reported issues, leading American Airlines employees Michael Woodward and Elizabeth Williams to investigate gate 32. Curiously, they reported encountering an empty plane at the gate, which contradicted the BTS's information that Flight 11 had not departed.
After sifting through air traffic control records, I discovered that a different flight had indeed pulled into gate 32 around the same time—an American Airlines flight 737—meaning that the empty plane they witnessed was likely not Flight 11 at all but another aircraft instead.