Urist Mc!!Dwarf!! told them not to step into the danger room, and they didn't listen. There's another child in the hospital with severe bone breakage and pale with blood loss from the training spears in the danger room and another with 10 something wounds all over his body, each one having atleast a broken bone and many torn open badly. That child also has about 7 infections and is somehow still alive.
Natural selection at work.