What causes flash floods? Here's how they get so destructive so quickly

Floodwater poured inside a Brooklyn subway station and formed a waterfall as deadly flash flooding hit New York City on Thursday. Multiple stations experienced delays and cancelations over the heavy rainfall, the MTA said. Thursday's rain led to deadly flooding in parts of in the city as it broke records and caused damage. At least two apparent storm-related deaths were reported. https://cbsn.ws/47MiixP | CBS News

Survival tips if you get trapped in a flash flood