UPDATE, 12:50: Part of an escalator at the Foggy Bottom Metro station fell apart around 9:15 a.m. during this morning's commute, leaving a hole in the unit. In the words of one witness on Twitter, the escalator "collapsed on itself and broke in [a] gaping hole with riders on it." As of around 12:30 p.m., Metro had fixed the broken steps on the escalator and had it functioning as a staircase with two-way traffic. The breakdown led to a massive bottleneck inside the station.

Metro confirms that the unit malfunctioned and that it was shut down as soon as a passenger reported it. The photo above shows workers at the base of the escalator in the aftermath of the breakdown.

According to Metro spokesperson Angela Gates, nobody was hurt in the incident.

Close Metro watcher Joel Housman hopped off a train at Foggy Bottom shortly after the breakdown. He tells TBD in a series of tweets, "I'm not sure whether to say fortunately or unfortunately but I had gotten off at Foggy once it already happened. Complete mess.... Took about 20 minutes for me to go from my train to above ground through the crowd. Got a good look at the crumbled stairs.... WMATA is VERY VERY lucky the 1 or 2 people who fell into the hold didn't get seriously cut or injured on the stairs' 'teeth'.... From what I heard, the one woman who fell in managed to get out on her own with little to no injury."

Unsuck DC Metro has posted an anonymous account of the incident from an alleged witness, who says a handful of riders actually fell into the hole at the bottom of the unit.

The escalators at Foggy Bottom have been undergoing a massive rehab project aimed at replacing all three units. (There are no stairs at the station now, but they will be added as part of the project.) The Foggy Bottom station's escalators performed the worst among Metro's busiest stations in December, the most recent statistics available. One of the three escalators was already out of commission for replacement before today's incident; after today's breakdown, the station will probably have no descending escalator for the time being.

When announcing the escalator work back in January, Metro general manager Richard Sarles said, “While we regret the inconvenience to customers, after one year customers will benefit from three brand new escalators they can rely on. For the first time, the station will have a staircase to improve passenger flow and increase capacity to move people through the station.”

If anything, today's incident proves the importance of the renovations.