There was radioactivity, and it was measured by USGS.
Did the USGS tell you that?
Thanks for the link.
It was precisely 9:59 a.m. on Tuesday, September 11th, 2001, when someone somewhere pressed a button that sent a single coded radio signal to a small receiver inside the worlds smallest and most sophisticated explosive device ever invented; a neutron bomb the size of an apple located on the 80th floor of the North Tower of the World Trade Center in the largest financial center in the world; New York City exploded.
An unseen circuit closed and a primer fired, then one-millionth of a single second later, a terrible fireball formed on the 80th floor of the Tower. The fireball was small.
Less than six inches in diameter and burning at a staggering 10 million+ degrees, the fireball was a perfect shimmering sphere, unseen, made possible by a fusion reaction between Tritium and Deuterium leading to a very short lived fission reaction. Just 6 inches across, this was the latest technology we’ve developed. Micro Nuclear Devices.
Hilarious!