On Monday Washington D.C. received a month of rain in one hour.
It happened in the morning rush hour.
The National Weather Service said that the line of storms was a once-in-100-year event.
3.30 inches of rain fell at Reagan National Airport. Some areas received just over 4.0 inches in the D.C. area.
As a result of the rain there was a two-hour flash flood emergency for the region.