Just released video from a New York police helicopter reveals the horror of the terror attack on the World Trade Center as it happens. The 17-minute footage shows incredibly close footage of black smoke billowing from the towers in the biggest terror attack ever on US soil. "Holy shit," says one cop as the crew watches later as the first tower crumbles to dust from a helicopter landing pad. The video was obtained by the National Institute of Standards and Technology under the Freedom of Information Act and was sent with several photos anonymously to the Cryptome website. (More NYPD stories.)