can a fractured foot cause a death?
In extreme circumstances, complications from a fracture can cause death. (I'm not just thinking about the classic "my foot is broken so the lion got me" variation of this.) For instance, in a complicated fracture there might be a problem with the blood supply, which then might lead to gangrene, which then might lead to death. Or, a blood clot might form, turn loose, lodge somewhere else (close to the heart or to the brain) and cause death.
Only if it becomes infected and the infection is not treated.