What I read tells me that your belt tore. With no drive belt, your water pump was not running anymore, which explains the overheating. Since you lost the contents of your cooling system (replacing the coolant mix with water isn't the best thing for the long term), I would recommend that you do a coolant change, and take the chance to change your water pump, thermostat, hoses and perhaps even the radiator. This will save you a lot of trouble and will give you peace of mind in the future.
How did your interview go?