alternator workshop?

on my way home the battery light came on and then the car beeped and said alternator workshop.

any ideas what would have caused this to happen?
thanks in advance.

either a belt broke, the alternator failed, or the battery is dead. Check the belts to see if they are still on the car. IF the alternator is smoking or smells funny than its bad. If you have a multimeter check the voltage of the battery when the car is off and when it is running. Should be 12-12.8v when off and 14.0-14.5v when running.