Now for those of you who don't know or haven't already guessed, caesium-137 is radioactive as balls. Remember that, because it comes up later.
The hospital had hired minimal security to try and keep people away, because somehow the removal of the potentially hazardous equipment was tied up in litigation. However, one day the guard called in sick to catch a showing of Herbie Goes Bananas, which proved to be the chink in the armor of their bulletproof anti-theft initiative.
Huh. Well, this is certainly a film that exists.
Two scavengers named Roberto dos Santos Alves and Wagner Mota Pereira saw their opportunity and swooped in to steal whatever they could carry. "Whatever they could carry," as you can guess, turned out to be the caesium-137 radiotherapy unit, which they brought back home and promptly tore open like a Christmas present.
They removed the core and smashed it open, finding a blue glowing substance inside that mystified them. This was the caesium, and predictably, it poisoned the everloving shit out of both men, eventually causing internal damage, contact burns and the need for amputation. Luckily, they were able to take the exposed core to a scrapyard before any of that happened.
"Hey look, that girl could look after it for a while. Pass her a 20. We're creating jobs here."