@Eric Brown has the result right qualitatively. We can add some more quantitative and chemical information.
Step 3: When salt is added, the freezing point of the water is decreased at that point, so the ice melts to water. This is a colligative property; i.e. has only to do with amount of substance, and not the particular substance.
Step 4: As the melting water dilutes, its phase shifts back towards pure water, which has a higher freezing point.
Step 5: At some point, the phase shifts back to freezing at 0 °C, and the water re-freezes given the ambient ice at 0 °C.
This Wikipedia article shows you the phase diagram corresponding to my description:
NaCl phase diagram
As I said, my answer merely augments your already selected correct answer, but I thought this might be useful additional information.