Sounds similar to what just happened to mine about an hour ago.

Wife was at the bank and the Sentry Key indicator above the temp gauge came on and the warning bell started going off. (like you left headlights on)

She turned it off, and started it back up but no change. When she got home she came in to tell me what was up and by the time I got out there to check, it won't start at all now. Dash lights up and the bell starts ringing but it won't turn over. I tried both keys.

I hooked up my Superchip to check codes -
UO168 Lost Communication With Vehicle Security Control Module (skreem-wcm)

I disconnected the battery and giving it a few minutes to see if it will reset or something.

Really hoping I don't have to pay to have it towed.

Beel