In the recent past the Iranians claimed shooting down a couple of US drones. The US responded that no drone was missing. This time at least, a drone is missing. Perhaps it malfunctioned and went down. In any case, the RQ-170 drone does not have the advanced features of the B-2 Stealth Bomber. For example, it does not have sharp edges and some other concealment features. It was deployed over Afghanistan with the understanding that some specimens will fall into the wrong hands. This is not a devastating loss.
Wes Craven, director of 'Scream' and 'Nightmare on Elm Street', dies 76 (Haaretz)
from the article: U.S. says 'no indication' Iran shot down reconnaissance drone