Bobcat4: . . . "Minimum Safe Altitude Warning (MSAW) is a ground-based safety net function of an ATC radar data processing system. MSAW is intended to assist in the prevention of controlled flight into terrain accidents by generating, in a timely manner, an alert of a potential or actual infringement of a minimum safe altitude. The MSAW function, using software in ATC computers, alerts ATCOs when radar returns indicate an aircraft penetrating or about to penetrate the minimum safe altitude."
This warning does not apply to decaying airspeed or ground speed [Propellor planes fly slower than jets]; and when the airplane went more than 1 dot below glide path and had dropped out of the sky less than 2 miles short of the runway, this system couldn't alert the tower controller of an adverse flight profile trend in time to have changed the outcome of this crash.