Last night while commuting on metro, I (and everyone else on my train platform) received a wireless emergency alert about flash flooding that could occur in the area. I was preoccupied thinking about the WEA system, and how it was kind of neat to see everyone on the platform get the message, and then two minutes later see everyone on the arriving train receive it as their train came out of the tunnel and they had access to cell service. I figured I was safe where I was, and that the alert would only impact people near streams or areas with poor drainage. Plus, I'd been getting text alerts from the DC alert system and my home county all day about severe thunderstorms and flash flooding- but hadn't seen or heard of any flooding or standing water outside of areas that get affected any time it rains, and that I don't need to cross to get home.
It wasn't until I got home that I realized I narrowly missed being in a dangerous situation. These photos were taken in a station I passed through, not long after I was there - more details are in this article: http://wtop.com/sprawl-crawl/2016/06/flooding-closes-cleveland-park-metro-station-photos/slide/2/
It can be hard to remember that abnormally large volumes of rain can create flooding, even in areas that can handle average volumes without trouble. I'm glad I made it home safe, and I think I'll pay more attention to wireless emergency alerts in the future, even if I've been getting similar alerts from opt-in systems all day.