In a medical building in the Washington, D.C., area, a freezer of radioactive material sat in a hallway unguarded.
How did NBC News find it? By carefully reading a U.S. government Web site belonging to the Nuclear Regulatory Commission. There, NBC News found more than a dozen recently filed documents identifying hospitals, universities and businesses that store dangerous radioactive materials — complete with detailed floor plans and room numbers.
"It's mind-boggling that some three-years after September 11, we can still find detailed drawings like this," says Charles Ferguson, a former State Department official and dirty bomb expert now at the Council on Foreign Relations.
"This Web site can provide a road map to a terrorist. It shows them exactly where they need to go to find dangerous radioactive materials," says Ferguson.
One floor plan was helpfully color-coded, with red indicating the most potent material. On another, an East Coast hospital revealed that its radioactive material is near the blood bank. So, NBC checked the room number listed, and got right up to the door.
For security reasons, NBC News is not identifying the facilities. Some hospitals and universities, which were required to provide the information to the NRC, were stunned to learn the floor plans were posted on a Web site.
Especially troubling to experts — information, including a map and photo, making it easy to find a Texas business storing large amounts of deadly materials.
According to Ferguson, there's enough material at this facility to make "probably at least a dozen" dirty bombs.
So how could this happen?
An NRC official says it's because of the public demand to know where radioactive material is kept.
"The floor plan of itself is, in our minds, not a significant amount of information to lead to successful terrorist attacks," says NRC security official Roy Zimmerman.
The NRC adds that radioactive material often is housed in heavy machines and not easily removed.
But Monday there was an unexpected development: Six days after NBC News showed the documents to the NRC, the agency shut down that part of the Web site, which may have been inadvertently providing a road map to terror.