A recent storm survey by the National Weather Service (NWS) in Allegheny and Westmoreland Counties determined that the damage was caused by straight-line winds, not a tornado, despite an earlier tornado warning. The survey team assessed the damage from West Mifflin to North Huntingdon and found that winds between 60 to 70 mph were responsible for the destruction. These high-speed winds caused considerable damage to structures and trees in the affected areas.