Blue Cherenkov Radiation: Chernobyl vs WTC
From the Chernobyl series-- a blue beam of light going up from the exploded reactor:
Remember the WTC "Tribute in Light"?
To be clear, the lights at the WTC were added in much later after 9/11 with searchlights, but the similarity with the Cherenkov radiation as Chernobyl is bizarre given our suspicion that the WTC demolition was nuclear!
Now, it should be noted that there doesn't seem to be the same kind of massive release of radiation at the WTC like was at Chernobyl. No one died from, or showed symptoms of, acute radiation poisoning at the WTC like at Chernobyl.
Of course there were massive increases in cancer at Chernobyl and the Ground Zero workers at the WTC developed high rates of cancer.
Assuming nukes were used at the WTC, they were clearly cleaner, used less nuclear material, were much more efficent and much more focused on destruction.
Chernobyl was a very very very dirty nuclear explosion -- a relatively small nuclear explosion that spread massive amounts of radionuclides all over.