[["a sad tragedy in american history", 45.0], ["On September 11, 2001, suicide hijackers crashed US passenger jets into the Twin Towers of the World Trade Center, causing the collapse of both towers, & killing thousands of people. A 3rd jet was crashed into the Pentagon, & a 4th hijacked flight was thwarted by passengers & crew & crashed in Penn.", 9.0]]
what happened on september ninth two thousand one
history