Why Couldn't They Have Hijacked The Truck With The Less Dangerous Radioactive Material?

Good morning! “A truck carrying ‘extremely dangerous’ radioactive material has been stolen in Mexico, authorities said Wednesday. The vehicle was transporting the radioactive isotope cobalt-60 from a hospital where it was being used for radiotherapy, the International Atomic Energy Agency said. Experts said that if the material gets into the wrong hands it could be turned into a ‘dirty bomb’ and potentially spread cancer-causing radiation across a wide area.”