A student is calling.

Student is calling from the airport.

Student is calling to say they will miss curfew.

[http://emergencyphone.wikia.com/wiki/Student_is_calling_on_a_night_out. Student is calling on a night out.]

Student has had a minor accident or is ill.

Student has missed a flight.

Under 18 student wants permission to travel/stay somewhere overnight.

There has been a SERIOUS incident.