2002 Chrysler Concorde Transmission failure

I had been showing a MIL code PO700 (740) TCC solenoid problem for the last week or so. I had it checked but nothing showed so we decided the sensor was defective and was sending message in error. Obviously not because I had a failure Saturday night. Immediately before failure I heard what I thought was a gurgling sound that I thought was coming from the heater core, almost instantly I lost my previously normal functioning transmission. After sitting turned off for a few minutes I was able to move the vehicle to a more secure location about 8 or 10 mph and had it towed. How serious might this be? Rebuild or replace?