UPDATE: The fine folks at the Sunlight Foundation managed to capture the whole thing on video. Take a look: DCist reader Todd sent in this image of a large section of metal duct work that fell down on top of several parked cars this morning in an alley behind 1250 Connecticut Ave. NW (adjacent to 1800 N St. NW). The incident happened at about 10:30 a.m. Thankfully, no one was injured, but it’s scary to…