I came across this account of the Tribute in Light, those blazing towers of floodlit clouds and sky used by Manhattan to memorialize the fallen World Trade Center: "The beams were visibly filled with birds for their entire height, looking like clouds of bugs. Their twittering was audible. There were so many birds, it was impossible to track any one individual for any length of time. I did see one bird that circled in and out of the uptown beam six times before I lost track."

The birds, in other words, had been fatally mesmerized, often spiraling thereafter to the ground – or into the windows of nearby buildings. A kind of bird-tornado.

BLDGBLOG: The birds