@ ROMEO E.T.
the only GPWS alerts that would have been heard are "SINK RATE... SINK RATE....SINK RATE"
You could be wrong, if they use E(nhanced)GPWS.
http://www51.honeywell.com/aero/comm...tion_(TCF).avi
In that case a TOO LOW TERRAIN is also possible:
"Descent below unsafe radio altitude while too
far from any airport in the terrain database."
I know that the boundary at 18R for this warnings is quite close to the airport.
Rgds
emjanssen