battery dead & key stuck 01 regal

I have a 2001 regal ls with the 3.8 motor . I started the car and left it running to warm up.When I returned the car had died and it seemed like the battery was dead.I tryed to turn the ignition switch to the lock position but it would only move to the start or run position.finally it turned to the lock position and won't move again. I have tried two different keys with the same result.I am hoping the two problems are connected by means of the anti-theft system witch may have been triggered by the dead battery.I have been told that there is some kind of special way to release the anti-theft lockout by pushing a specific combination of buttons or controls within the car. ie:horn x2 ,driver window up ,left blinker then right etc.. I have already bought a replacement battery but am not sure about the ignition switch.I have had no problems with either the switch or the battery till now.Are these problems related or is this coincidental.Please help .....

Welcome to AF.

When the battery goes South it is normal to get key lock up. Install the new battery and it will be fine.

Also, once running I would recommend getting the charging system (alternator) tested just to be sure its all OK.