4 -20mA Analogue input help

[sayzer]

In case the ground return is somehow opened, won't this destroy the pic?

Ioannis

Yes, I think so; Most likely it will burn the i/O circuity of the pin.
If not, you get reset.

And, most of the time, people tend to connect sensors without powering-off the reader device. So there is high possibility that what you said is indeed a highly possible scenario.