Stupido thieves or not, a hospital in Tijuana & their contracted shippers still got some splaining to do. From CNN:

The container holding cobalt was found about a kilometer away from the truck and had been opened, said Juan Eibenschutz Hartman, head of Mexico's National Commission for Nuclear Security and Safeguards.

There was less than 40 grams (1.4 ounces) of the hazardous material inside.

Authorities are guarding the area and have set up a 500-meter perimeter around it, Eibenschutz said. They are evaluating whether any residents were exposed.

Cleaning up the area could take weeks, he said, because they don't have robotic equipment they would need to quickly collect the dangerous cobalt. They're coming up with a plan and considering asking for help from the International Atomic Energy Agency, the United States or Canada.

The IAEA announced the theft on Wednesday.

Mexican authorities told the IAEA that the truck, which was transporting cobalt-60 from a hospital in Tijuana to a radioactive waste storage center, was stolen Monday in Tepojaco, near Mexico City.

An early theory is that the thieves were unaware of what exactly they had taken.

"At the time the truck was stolen, the source was properly shielded," the IAEA said. "However, the source could be extremely dangerous to a person if removed from the shielding, or if it was damaged."

But Eibenschutz said the truck wasn't properly set up to transport the radioactive material, since it didn't have a GPS for tracking or other necessary equipment.