September 11, 2001 remains one of the deadliest days in our nation’s history—more than 2,700 American citizens were killed in the terrorist attacks that struck U.S. soil. This date also remains the deadliest day in our nation’s law enforcement history—72 peace officers were killed in the line of duty.

Ten years later, the National Law Enforcement Museum hosted the second installment of its lecture series entitled ‘Witness to History: September 11, 2001,’ to shed light on some little-known facts about 9/11 from a law enforcement perspective.