2007 Chevrolet Suburban 1500 LT

Yesterday, I tried, unsuccessfully, to program a secondary keyless remote. Did not think too much about it, until this morning, when I went to crank the car and the vehicle was completely and utterly dead. NOTHING IS WORKING. Even the security light on the dash is not showing anything. DEAD, BLANK, DARK...Thinking that the battery had drained, I proceeded to JUMP start the vehicle to no avail. It is to be noted that I woke to sub 30 degree rainy weather.

I am thinking that I did something to the security system, inadvertently, which has caused the vehicle to go completely DEAD.

Any suggestions before I have to TOW this paperweight to the dealership?

Any help is appreciated.