Possible tornado sweeps through DC, surrounding areas; thousands of utility customers left without power Elinor Aspegren, USA TODAY Replay Video UP NEXT A possible tornado swept through the Washington D.C., area Thursday night, passing through the National Mall and disrupting flights at Reagan National Airport. Forecasters were still trying to determine if the wind damage that occurred in Virginia, the district and Maryland was caused by a tornado or straight-line winds. The National Weather Service issued a tornado warning until 9:30 p.m. local time, and said about ten minutes after the warning had expired that the worst of the storms had passed.