On Sept. 11, 2001, commuters streamed into Manhattan under a clear-blue late-summer sky. By the end of the day, a pall of acrid, dark smoke hovered over downtown.

Ten years later, the toxic cloud has long since lifted, and new skyscrapers are under construction at “Ground Zero” to replace the iconic Twin Towers that were destroyed by the terrorist attacks. But the impact of the attacks still lingers on how lawyers do business and courts dispense justice.