I'm watching this on TV right now, apparently there were cars headed to work this morning and a pipe burst. They are doing helicopter rescues right now. No one has died nor are there any serious injuries, but the concern is hypothermia because it's really cold out there.
I'll keep updating as more info comes in.
You can watch live here
Montgomery County fire department spokesman Pete Piringer said at least a dozen people had been rescued from their vehicles as crews struggled with the swift water to reach more cars. No injuries were reported.
Authorities said it was a 66-inch water main that broke on River Road near the Congressional Country Club in Bethesda.
Morning temperatures in the area were well below freezing.
Right now they are talking about how Obama was right to spend so much time talking about infrastructure during the campaign.
[Update 10:14 AM]: Fine, I put "breaking" in the title.
Also, reports are that the rescue is very difficult right now, but the people who were trapped in their cars were very calm.
[Update 10:22 AM]: The water has been shut off from what I understand. Also, this sort of thing is apparently common in that area, but nothing this big before.
[Update 10:27 AM here's more info from the Washington Post:
The break, near the Congressional Country Club, sent "a four-foot wall of water" onto River Road, Piringer told CNN. "About 12 to 15 vehicles became enveloped in this wall of water."
The pipe is 44 years old, WSSC spokesman Jim Neustadt said. Both age and the recent cold snap could have contributed to it breaking. Neustadt said that Montgomery County fire officials had ruled it was not safe for WSSC workers to enter the deep and rapidly moving water in order to turn off the valve. In order to halt the flow of water, he said, "we have to back it up to another valve up the line."