initial sighting indicating airliner on final approach for main runway

On the date indicated above, I was employed as security at the Florida Light & Power plant.  While checking the perimiter fence on the east side, I turned off the golf cart, When I observed a greenish large light approaching from the west, the rate of speed , decent, angle indicated that this was an airliner on final approach.  The ceiling was  approx six to seven thousand feet w/very scatterd clouds, yet the light seemed to be hazy as if in a fog, when it came over the intercoastal waterway, appox 1/4 mile from my location, it made a sharp 90 degree turn to the south accelerated faster than any aircraft that I have ever seen, I viewed it for approx  5/10 seconds until it vanished. No engine noise was heard, If this was seen by me, it had to have been seen by the control tower as it was no more than 600ft agl.  I looked for any reports on the radio, newspapers, tv nothing was mentioned.. brief background, college grad/ aa/bs, military vet (us army).