On March 22, 1992, USAir Flight 405 departed from LaGuardia Airport in icy conditions, and a few minutes later, stalled and crash-landed, killing 27 passengers. A year later, the National Transportation Safety Board (NTSB) completed its investigation and published Aircraft Accident Report AAR–93/02 in which it concluded that the crash was caused by a build-up of ice on the plane’s wings just after take-off. Despite the fact that de-icing fluid had been applied at the gate, a departure delay after the plane taxied onto the runway allowed ice to re-form on the wings, leading to the crash. Shortly after that report was published, airports around the world quickly modified their protocols, de-icing planes just prior to take-off rather than at the gate.