Hello folks!

I am using a PIC16F871, with a voltage regulator (with power switch) for Vdd. I want to use RA4 as open drain output connected to a buzzer (BZ) which is powered directly from battery. Will I fry my 871 when Vbatt is connected to the buzzer, but no Vdd is present at the PIC? Or will it start buzzing when Vdd is not present?
In other words: What will happen when the switch is opened in this schematic:
Code:
F871
----
    |        ____
RA4 |-------|_BZ_|--------------------------      
    |                                      |   
Vdd |------\ -----------+5V ---regulator -------- +7.2V
    |     switch
----
  |
GND
Thanks for your help!