The floodwaters that inundated Ellicott City came with a warning, but still took its historic Main Street district by surprise. Witnesses described waters rising several feet in a matter of minutes.
6:45 p.m.: Rain begins to fall in Ellicott City.
7:18 p.m.: National Weather Service issues flash flood warning across Howard County, Baltimore and southern Baltimore County.
7:30 p.m.: Heaviest rain moves in to Ellicott City, with 4.56 inches of rain over the next hour.
8:15 p.m.: Patapsco River begins to swell, rising 6 feet in an hour.
8:45 p.m.: As rain tapers off, floodwaters begin to surge down Main Street, with nearly 6 inches of precipitation in two hours.
9 p.m.: As the flash flooding on Main Street eases, the Patapsco River crests, rising 14 feet in an hour and a half.
11:59 p.m.: Floodwaters subsided, Howard County Executive Allan Kittleman calls for a state of emergency.