REUTERS/Gleb Garanich
Workers place a container with spent highly-enriched uranium on a truck at a nuclear research facility in Kiev March 24, 2012.
The thieves probably weren't going after the contents though.
"It could be," one federal official told NBC "that whoever stole the truck had no idea what was inside and was more interesting [sic] in getting a truck."
IAEA spokeswoman Gill Tudor told NBC News that medical ramifications from these heists have occurred in the past:
"Such thefts are not uncommon, and the thieves do not necessarily know what they have in their possession in addition to the vehicle that may have been the original target. In some cases, for example, radioactive sources have ended up being sold as scrap, causing serious health consequences for people who unknowingly come into contact with it."
The isotope is used for killing certain kinds of pathogens and for industrial imaging (essentially, x-raying buildings), so it's effect on the human body is incredibly deleterious and can cause cancer.